Triangular Zone Research Articles

Cytonyssus troglodyti sp. n. (Acarina: Cytoditidae) from the Nasal Passages of the Carolina Wren, Thryothorus ludovicianus

Cytonyssus troglodyti sp. n. is described from the nasal passages of the Carolina wren, Thryothorus ludovicianus, from Louisiana. Although similar to both Cytonyssus andrei and C. temenuchi, the new species differs in the structure of the chelicera, the shape of the dorsal punctate areas, the chaetotaxy and solenidiotaxy of the legs, and the shape of the idiosoma. This is the first report of this genus from the Troglodytidae and from North America. Examination of the nasal passages of a specimen of the Carolina wren, Thryothorus ludovicianus, revealed the presence of mites of the genus Cytonyssus. These differ from other species of the genus and they are described herein as a new species. In the following description all measurements are in microns. The range of measurements of the paratypes and their means follow the values for the holotype in parentheses. Drawings were made with the aid of a camera lucida. Cytonyssus troglodyti sp. n. (Figs. 1-6) Description (based on the holotype 9 and 3 9 paratypes): Acarina; Sarcoptiformes; Cytoditidae Oudemans, 1908; Cytonyssus Fain, 1960. Female: Body small, white in color, angulate anteriorly, rounded posteriorly. Length of idiosoma (gnathosoma included) 350 (320 to 360, 345). Maximum width of idiosoma 280 (250 to 285, 270). Dorsum: A triangular punctate area on the propodosoma, a large rectangular punctate zone on the middle opisthosoma, two lateral punctate areas adjacent to this, and ventrally a small punctate zone connected or not to the rectangular punctate zone on the posterior margin of the opisthosoma. Two pairs of setae located on the anterior triangular punctate zone, 4 pairs on the lateral punctate zones. Venter: Several punctate zones present, mostly in the intercoxal fields. Epimera I very short, fused to form a well-developed sternum. Epimera II, III, and IV free. Anus ventral in posterior region of body. Genital vent longitudinal, located between epimera III and IV, apodemes not distinct. Bursa copulatrix short, indistinct, copulatory orifice posterior to anus on posterior margin of venter. Gnathosoma: Small, with structure as illustrated (Fig. 2). Chelicera very small, indistinct in most specimens, terminating in a Received for publication 14 September 1971. fork-shaped structure with three unequal points. Legs: Length of legs I, II, III, and IV 120 (117 to 120, 118), 116 (112 to 116, 114), 117 (113 to 117, 115), and 125 (120 to 128, 124), respectively. Tarsi I to IV with pedunculate ambulacra. Tarsus I with 6 large transparent curved spines located apically and 4 very fine setae on the dorsal and ventral aspects. Tarsi II, III, and IV each with 6 large curved spines located apically and 3 smaller spinose setae. Tibiae I to III with 1 short spine e ch. Tibia IV with 2 short spines. Genu I with 2 short spines. Genus II and III with 1 short spine each. Genu IV, femurs, and trochanters devoid of setae. Tarsus I with 1 large and 1 smaller solenidion measuring 6 to 8 and 4, respectively. Tarsus II and tibiae I, II, and III each bear apically on the dorsal surface 1 very large solenidion measuring 15 to 17, 16 to 18, 12 to 14, and 10 to 13, respectively. Solenidions on tibiae I and II with slightly swollen bases. Two very small solenidions on dorsal surface of genu I and a single solenidion on genu II. Remaining leg segments devoid of solenidions. Male, nymphs, larvae: Unknown. Host: Thryothorus ludovicianus, the Carolina

Incisional wounds in palatal epithelium in guinea pigs.

abstract – Standardized incisional wounds were made in the palatal mucosa of 54 adult, male guinea pigs, in order to study the reaction to injury of orthokeratinized epithelium. The wound area was studied histologically 2, 4, 6, 12, 24, 48, 72, 120, and 240 hours postoperatively. Initial cellular changes occurred as early as 2 hours after wounding. The changes consisted of a reduced cytoplasmic stainability with pyknosis and karyorrhexis covering a triangular zone (reactive zone) along the incisional cleft involving the lower part of stratum corneum, stratum granulosum, and the upper half of stratum spinosum. It is suggested that this cellular reaction represents an “induced keratinization”. After 6 hours the reactive zone was delineated from the adjacent, normal epithelial cells by a demarcation zone consisting of 2–3 layers of hyperchromatic, elongated cells. The first signs of migratory activity were noticed from the basal and lower spinous cells 12 hours after wounding. Eighteen hours postoperatively a fusion of the horizontally migrating epithelium had occurred in all wounds examined. By 18 and 24 hours the demarcation zones of the two wound margins met and formed a continuous zone at the base of the incision to constitute the superficial cell layers of the fusion area. A gradual increase in number of cell layers was seen in the fusion area from 24 hours onwards, reaching normal height and differentiation of the epithelium at 120 hours. During the same period epithelial cells migrated from the basal cells into the fibrin‐filled connective tissue wound. By 240 hours the migratory activity was reduced to focal single cell migration. Although a normal cellular differentiation was present in the epithelium of the wound area at 240 hours, the characteristic histo‐architectural pattern of the area had not yet been re‐established, and no PAS‐positive basement membrane was found.

A Modified Reflection Coefficient for Layered Media

The energy leaving an antenna is considered as a series of rays reflected to a distant antenna. Each ray forms many reflected rays at each layer and invariant imbedding is used to study those rays of interest (i.e., rays forming a triangular zone connecting the antennas) and all others are considered lost.The modified reflection coefficient differs by several dB in some cases from the conventional plane‐wave reflection coefficient.

Studies in the Talchir Flora of India - 3. Stellapollenites: A new monosaccate pollen genus from the South Rewa Gondwana Basin

A new monosaccate pollen genus, viz. Stellapollenites is described from the Talchir Stage of the South Rewa Gondwana basin. The saccus is attached sub-equatorially on both faces of the body and the triangular attachment zones on the two faces are mutually reversed. A new series, viz. Amphisacciti is proposed to include stellapollenites and other pollen genera with a brief comment on their organizational trends.

ARTERIAL VASCULARIZATION OF THE SOFT TISSUES OF THE HAND

The central area of the palm contains a triangular zone which is poorly vascularized. Because of the paucity of blood vessels, extensive undermining of this flap may invite delayed wound healing or frank necrosis. Appreciation of this important anatomical weakness has led the authors to adopt the principles of limited undermining of the skin and subcutaneous tissue of the palm or, following undermining of an extensive degree, the primary excision of nsomn-viable marginial tissue and coverage by skin grafts or pedicled flaps.

Relics of the Mt. Pelé Eruption of May 8, 1902

THE uncouth and sinister-looking volcano of Mt. Pelé (or La Montagne Pelée) occupies the north end of Martinique and rises to about 4,400 ft. The rest of the island consists of lavas, tuffs and limestones which have yielded a fauna of Miocene, probably of Helvetian age. Mt. Pelé had minor eruptions in 1792 and 1852, but began to give warning near the end of April 1902. The great eruption or nuée ardente came at 8 p.m. on May 8,1902. St. Pierre, the one-time capital of the island, with thirty to forty thousand inhabitants, six miles south of the volcano and just within the triangular zone of destruction, was overwhelmed. Further destructive nuées occurred during 1902 and 1903, and they were renewed during 1929 and 1930, when avalanches of incandescent stones, some of them as large as haystacks, were projected down to the sea at the Riviére Blanche.