Middle Third Of Body Research Articles

Deurithitrema gingae n.g., n.sp. (Digenea: Plagiorchioidea) from the kidneys of a salt-water crocodile (Crocodylus porosus Schneider) from Australia

The name Deurithitrema gingae n. g., n. sp. is proposed for worms from the kidneys of one Crocodylus porosus from Darwin, Northern Territory, Australia. The following combination of characters distinguishes the new genus from all others: prepharynx very short; oesophagus absent; caeca reaching to posterior end of body; testes tandem in middle third of body, contiguous or amost so; cirrus-sac large, over-reaches ventral sucker, contains bipartite seminal vesicle, prostatic regions and ejaculatory duct with spines around its opening into genital atrium; genital pore immediately in front of ventral sucker; uterus coiled to posterior end of body; vitellaria lateral from ventral sucker to slightly behind testes; excretory vesicle small, receiving a single ventro-lateral duct from each side behind end of uterine loops. Deurithitrema belongs to the superfamily Plagiorchioidea Dollfus, 1930. It superficially resembles a number of genera, but its relationships within the superfamily are obscure.

A New Species of Westella (Trematoda: Opisthogoniminae) from a Mexican Snake

Westella tabascensis sp. n. (Trematoda: Opisthogoniminae) from the mouth of a snake (Coniophanes quinquevittatus) from Tabasco, Mexico, is described. In July 1958, seven specimens of an apparently undescribed species of Westella were recovered from the oral cavity of a snake (Coniophanes quinquevittatus) in the Mexican state of Tabasco. Six were prepared as whole mounts, and the seventh was serially sectioned. The measurements in the diagnosis are of the holotype followed by the size ranges in parentheses. All measurements are in millimeters. Westella tabascensis sp. n. Figure 1 Host: Coniophanes quinquevittatus (Dumbril, Bibron, and Dumbril). Location: Oral cavity. Locality: 15 miles south of Villahermosa, Tabasco, Mexico. Holotype: USNM Helm. Coll. Paratypes: Helm. Coll. Instituto de Biologia, Mexico, D. F.; Dept. of Zoology, Louisiana State University; author's collection. Diagnosis: Body broadly rounded anteriorly, tapering sharply posteriorly; 2.2 (1.8 to 2.34) long, 1.1 (0.85 to 1.1) in maximum width at level of pharynx. Oral sucker subterminal, 0.456 (0.32 to 0.48) long, 0.47 (0.35 to 0.47) wide. Prepharynx moderately long. Length of pharynx 0.152 (0.15 to 0.165) width 0.216 (0.15 to 0'.22) at anterior margin, tapering posteriorly. Esophagus very short. Intestinal ceca extend to near posterior end of body.. Acetabulum 0.27 (0.248 to 0.27) long by 0.318 (0.234 to 0.318) wide. Acetabulo-oral sucker ratio, 1:1.5. Testes spherical, diagonal, in posterior portion or middle third of body. Anterior testis 0.242 (0.23 to 0.30) long, 0.292 (0.25 to 0.292) wide. Posterior testis 0.254 (0.23 to 0.30) by 0.33 (0.25 to 0.33). Cirrus sac anterosinistral to acetabulum, long, slender, 0.445 (0.42 to 0.55) in length by 0.051 (0.05 to 0.068) in maximum diameter, with angular bend anteriorly; contains small seminal vesicle and prostatic cells. Genital aperture immediately posterior to acetabulum, somewhat to left of midline. Ovary 0.292 (0.26 to 0.292) long, 0.254 (0.234 to 0.26) wide; in acetabular region or slightly preacetabular. Small seminal receptacle and ootype posterior to ovary. Vitelline follicles about 0.064 (0.027 to 0.095) in diameter, dorsally located in cecal and intercecal zones, from level of pharynx to posterior margin of testes. Uterus fills intercecal space posterior to acetabulum. Eggs numerous, 0.012 to 0.016 X 0.024 to 0.026.

Some Delayed Effects of Partial-body Irradiation in Mice of the RF Strain

SummaryThe effects of partial-body irradiation on life-span and incidence of disease were studied in young adult female RF mice treated as follows: 100 r x-rays to whole body, 300 r x-rays to whole body, 300 r x-rays to upper third of body, 300 r x-rays to middle third of body, 300 r x-rays to lower third of body, and non-irradiated controls. The mean survival-times of the aforementioned groups were 17·8, 15·2, 18·7, 18·6, 18·4 and 19·2 months, respectively. The incidence of thymic lymphoma was 25, 30, 11, 14, 19 and 19 per cent, and of myeloid leukaemia, 5, 15, 3, 3, 4 and 5 per cent. Partial-body irradiation induced lens opacities and ovarian tumours, but only when the lens and ovaries, respectively, were exposed.