The Cambrian rocks described in this paper lie north of the River Severn between the Wrekin Fault, that runs along the north-west flank of the Wrekin, and the Church Stretton Fault which passes west of Charlton Hill (map, PI. 38). A few exposures on the south-east side of the Wrekin are also mentioned. The area is bounded on the north in part by the outcrop of the Rushton Schist and in part by the Uriconian rocks of Charlton Hill to the south of which a small inlier of these older rocks forms the minor elevation of Brom Hill and is entirely surrounded by the Cambrian beds. The south-eastern part of the area is covered by the Coal Measures of the small coalfield of Dryton, south-east of which we also note the occurrence of an Upper Cambrian ( Ctenopyge ) fauna in Dryton Brook.

An account of saltation in the older parts of cultures of Diaporthe perniciosa strain DH C was given in an earlier paper (Horne and Das Gupta , 1929). The main features of this saltation were its occurrence in every cultural generation at a definite age ; the gradual transformation of the whole parent mycelium into the saltant DH F ; the absence of visible indications of saltation in the body of the parent culture ; and the inability of the saltant, which spreads relatively fast in fresh medium, to outgrow the slow-growing parent. While attempting to discover if there were any change with age in the nature of the branching of DH C hyphae concomitant with the appearance of saltation, it was found that viable hyphal tips from the advancing mycelium of DH C usually develop into DH F . Very minute fragments of older mycelium were also found to give rise to DH F when grown in fresh medium. Hence there was the possibility that DH C might be an intimate association of hyphae of two different characters DH C and DH F , with the DH C dominating the form of growth of the latter. It was therefore thought advisable to make a careful study of the behaviour of DH C and DH F in both separate and associated culture. Preliminary experiments with individual cultures of DH F showed that inocula taken from all parts usually bred true. On occasions, however, some inocula developed as mixed growth of the DH C and DH F , but no relation could be observed between the nature and position of inoculum and the occurrence of mixed growth. Attention was therefore devoted to the DH C culture. The results presented in this paper relate chiefly to the behaviour of DH C and the effect of inoculating DH F with DH C mycelium.

Among the problems presented by the bird’s skull and which we have attempted to solve, are the following :— 1. Why the cartilaginous plate in the orbito-temporal region (Gaupp, 1906, termed it the planum sphenolaterale) separates the first or profundus branch of the trigeminal nerve from the second or maxillary branch; this would be the position of a processus ascendens which the bird does not possess, while a pila antotica, which is supposed to be present in the bird, should be situated in front of the profundus branch; 2. Why the glossopharyngeal and vagus nerve-roots are separated by a cartilage which encloses the tympanic region, and what is the nature of this cartilage; 3. How the olfactory nerve makes its way into the nasal capsule, whether it traverses a part of the orbit, and what happens to the orbital cartilage in this region; 4. Why the internal carotid arteries pass through peculiar foramina in the cartilage on each side of the skull before penetrating into the cranial cavity through the hypophysial fenestra; 5. How the turbinals of the nasal capsule can be compared and brought into line with those of other forms.

We have made this attempt to describe and interpret the endocranial cast of Sinanthropus in deference to the wishes of Professor Davidson Black.* When he submitted to the Royal Society his preliminary report (Black, 1933, a ), he explained to us that he did not regard it as a disadvantage that his paper was incomplete, because it opened the way for those who had opportunities for comparing the cast with those of other human fossils and actual brains of primitive men and apes, to undertake the necessary work of comparison and interpretation, and we willingly undertake this duty. Each of us has independently studied the actual fossil skull in the Union Medical College at Peiping and examined the beautiful cast made by Professor Davidson Black from the actual fossils, and we should like to express our gratitude to him for these opportunities and many other kindnesses which he showed us. In studying the endocranial cast obtained from the Piltdown skull one of us (G.E.S.), years ago, was impressed by the extraordinary resemblance presented by the form of the brain in this extinct member of the human family to that of the primitive brain of a modern human being, a Sudanese negress (Elliot Smith, 1927, figs. 40 and 41). The other (J.L.S.) was impressed by the remarkable likeness to the endocranial cast of Sinanthropus of the brain of the Bushwoman, described in 1865 by Professor John Marshall. The recognition of these facts adds particular importance to the consideration that both the authors of this communication have served an apprenticeship to the task by examining large series of primitive brains, aboriginal Australians (J.L.S.) and Sudanese negroes (G.E.S.), and have devoted some attention to the comparison of the brains of the anthropoid apes and primitive men. In attempting to interpret the significance of the endocranial cast of Sinanthropus special attention must obviously be paid to comparison with the casts of Pithecanthropus and Eoanthropus . The comparison with the brains of the larger apes is also important, throwing light as it does upon the characters one ought to expect to find in extremely primitive human brains. In attempting to convey some real conception of the nature of the form of the brain we have resorted to the use of series of contours, figs. 10-14, so that the reader at a glance can obtain a graphic expression of the distinctive peculiarities of form. * The misfortune of his premature death deprives us of the pleasure of presenting this memoir to him.

The hedgehog ( Erinaceus europceus ) is a common British and North European mammal, but no thorough investigation appears to have been made of the reproductive cycle of the female. The present account is designed to fill this gap and as a contribution to the comparative physiology of reproduction. Ecological data are not included. Hubrecht (1889), working at Utrecht on the embryology of the hedgehog, gives the breeding season as June to August and the number of foetuses as 4-8. He regards the hedgehog as a primitive type. Millais (1904) states that the hedgehog breeds twice a year in Great Britain, having its first litter in May or June and its second in August or September, the period of gestation being not more than one month. Five to seven young are born, which are blind at birth ; after about three weeks their spines harden and they assume adult coloration. The young are three-quarters grown by the time winter sets in. Barrett-Hamilton (1911) states that the earliest hedgehog pregnancies occur in April, but he does not include any records. Second litters are found between the middle of August and the end of September ; a late pregnancy is recorded on September 23 in Ireland and an early post-partum animal on September 28 in Scotland. There are generally four or five young, though they may vary in number from 2-9. The length of gestation is given as 4-7 weeks, but as most probably seven weeks on the authority of Lilljeborg (1874). Like Millais, Barrett-Hamilton states that the young are well grown in the same season. Both these writers describe the hedgehog as hibernating from late in November onwards ; the length and extent of hibernation are very variable, however, and the animal is not infrequently found walking about in the winter. In view of the restricted breeding season it seemed likely that the reproductive organs of the female, no less than of the male hedgehog (Marshall, 1911), would show marked changes between the anoestrous and breeding season conditions.

The seasonal changes in the genital tract of the male hedgehog, notably the enormous hypertrophy of the accessory sexual glands in the spring and summer, early attracted the attention of biologists. The first important account of the reproductive cycle was given by Marshall (1911) who described the histological condition of the testis at different seasons and found that the production of spermatozoa commenced as early as January and continued to the end of September. The summer and winter appearance of the prostate and Cowper’s glands was described by Griffiths (1890), and in 1926 Pellegrini published observations on the secretory cycle in the interstitial cells of the testis. Courrier (1927) studied the cyclic changes in the various organs and gave a full bibliography of work on the male hedgehog. Animals with restricted reproductive activity have already proved valuable for experimental research (Hill and Parkes, 1932 ; Bissonnette, 1932), and earlier workers recognized the suitability of the hedgehog in this connection. Marshall (1911), by castrating hedgehogs at various phases of the reproductive cycle, showed that the periodic hypertrophy and continued activity of the accessory glands was controlled by the testes, and Courrier extended and confirmed his findings. The hedgehog should prove useful in a wide range of experimental work, for, besides possessing remarkable accessory glands, it is probably the only mammal with abdominal testes that can be easily obtained in England and kept in captivity. Although the general nature of the reproductive cycle has been described, previous authors have been content to examine a few animals only, and it was therefore thought desirable to examine a series sufficiently large to provide an adequate quantitative basis for experimental work. In addition, the large number of immature animals obtained supplied information on the rate of development of the genital tract before the first breeding season.

Much attention has been given in the last few years to the effects of deficiency of vitamins D and A on dental and parodontal structure; extended clinical tests have been carried out; and the deduction has been drawn that a deficiency of these factors is a not infrequent cause of such common dental ailments as caries and pyorrhoea alveolaris. Vitamin C has received relatively little consideration in this connection; in fact doubt is expressed as to whether it has any practical significance for clinical dental disease, and difference of opinion exists even on the fundamental issue as to whether a deficiency of the vitamin is in any way injurious to the teeth. Thus, on the one side, Mrs. Mellanby (1929) found that lack of vitamin C had no influence on tooth structure in puppies, and concluded it was “improbable that the actual structure of human teeth is greatly affected by a deficient intake of vitamin C.” At the other extreme Howe (1920, 1921, 1923) claimed that by feeding guinea-pigs on a scorbutic diet he had been able to produce with regularity all of the better-known dental lesions seen clinically in humans, including alveolar resorption, spongy gums, pockets and pus formation, together with caries and irregularities in the teeth themselves. He drew the deduction that vitamin C deficiency is an important factor in the aetiology of human dental disease. It will be generally conceded that further work is necessary to clear up the present unsatisfactory position.

The present paper shows how a method of research hitherto but tentatively used by a few workers on the internal characters of Brachiopod shells has been elaborated and applied to certain Mesozoic genera of different families, and has resulted in establishing the relationships of the forms examined more satisfactorily than by methods hitherto employed. It embodies some results of two years’ research on the identification and classification of such numerous species of the Brachiopod families Rhynchonellidae, Terebratulidae, and Terebratellidae, as are found in Jurassic and Cretaceous rocks. At the present time less than half of the Mesozoic Brachiopods are specifically determinable, and little or nothing is known of their internal structure, their mutual relationship, or their evolution. This is probably because internal casts are rare, and in Jurassic and Cretaceous species the two valves are not as a rule found detached from one another.

The relation of the Leptostraca to other groups of Crustacea has long been a problem of interest, although the alliance with the Eumalacostraca has been amply justified (Claus, 1872, 1888, Calm an, 1909). Claus discussed the essentially Malacostracan form of the appendages of Nebalia , and the mode of feeding by the aid of these appendages has been shown (Cannon, 1927) to be a specialized modification of the type shown by the simpler Malacostraca (Cannon and Manton, 1927, Some of the apparent differences between the Leptostraca and the Eumalacostraca have recently been shown to be differences of degree rather than of kind. Thus the seventh abdominal segment of Nebalia is found also in the embryo mysid, but is partially or completely fused with the sixth segment in the adult Lophogaster and Hemimysis respectively (Ma n to n, 1928,a and b). Thus the basal number of abdominal segments in the Eumalacostraca as well as the Leptostraca may be seven. The presence of a large caudal furca in Nebalia may also be a difference of degree, if this furca is homologous with the embryonic furca of a mysid (Manton, 1928, a). Other differences, such as the presence of a fully formed carapace adductor muscle, of cephalic liver lobes, etc., require further investigation. Of the resemblances between the Leptostraca and Eumalacostraca, the mode of development of the former is said to resemble that of the Mysidacea, but the embryology of no Leptostracan has been adequately followed, and the recent work on mysid development has considerably modified many previous views on this subject.

In 1864 John Marshall, of University College Hospital, London, published in the ‘ Philosophical Transactions ’ an account of a brain of exceptional interest, that of a Bushwoman. The original documents and photographs relating to this brain were recently handed to Professor Elliot Smith by his daughter, Miss Marshall, On his advice these documents have been studied anew.* In making his drawings from these photographs the lithographer made some slight changes which convey an erroneous impression of the primitive features that confer exceptional importance on this Bushwoman’s brain. The progress of knowledge of this subject since 1864 enables us to interpret the photographs in another way and so make this interesting evidence available for the interpretation of such archaic forms of brain as are revealed in the endocranial casts ofPithecanthropus,Sinanthropus, andEoanthropus. The original photographs represent the dorsal, ventral, lateral, anterior and posterior aspects of both hemispheres and the medial aspect of the left hemisphere. There is no photograph of the medial aspect of the right hemisphere. In addition to the photographs of the brain there are photographs of the head before the removal of the brain, and fortunately a photograph of the left hemispherein situwithin the cranium. Marshall’s photographs are exactly the same size as the lithographic figures ; and he states that the figures agree in size with the preserved brain. He also gives measurements of the cerebrum taken from intracranial casts. There is a small discrepancy between the length of the cerebrum as measured on the photograph showing the brain in the cranium and the figures in his table. The amount of shrinkage is shown in fig. 25, Plate 3. In estimating the form and size of the outline of the endocranial cast of the Bushwoman figured in this paper, Marshall’s maximum figures are taken; allowing for this possible error, his illustrations enable us to reproduce the form fairly accurately. In Marshall' s table of measurements, in which he contrasts the European brain with the Bushwoman’s, the European brain is smaller in certain dimensions. This indicates that he specially selected an abnormally small European brain for comparison.