ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 45 



surrounds the posterior end of the body in the mature female and hides 

 the anus and the vulva, leaving only the tip of the tail free. It does 

 not occur in the unfertilized female. 



Structure of Onchocera volvulus.* — L. Kiilz and F. W. Bach com- 

 municate some notes on the structure of this Nematode ( = Filaria 

 volvulus), which is known to cause fibrous tumours and abscesses in 

 natives of Cameroon. 



Blood Filaria of Camel.t — Antonio Pricolo describes Filaria hsema- 

 ticacameli sp. n. from the blood of the camel. He has found the adults 

 as well as the larvas. The larvae are found usually, if not always, at 

 night. The parasites were found chiefly in the vessels of the lungs and 

 the testes, causing aneurism-like enlargements, apparently of little im- 

 portance. 



Spermatogenesis and Oogenesis in Sclerostomum.J — K. Kiihtz has 

 studied these processes in various species of Scleroatomum found in the 

 horse. He calls attention to the strong development of the rhachis in 

 the male ; it extends far into the maturation zone. In the female 

 the rhachis is much less strong and disappears before the beginning of 

 the maturation zone. There are eleven chromosomes in the nuclei of 

 the spermatagonia, twelve in the nuclei of the oogonia. The spermato- 

 cytes show five tetrads and a monosome. The first or second maturation 

 division is unequal. Six equivalent tetrads are seen in the polar body 

 formation. There is an expulsion of an achromatin residue of the 

 germinal vesicle. 



In the ejaculatory phase the spermatozoon is elongated, but in the 



uterus this degenerates into a spherical form which effects fertilization. 



In isolated cases a segmention spindle is seen without there having been 



r any antecedent union of pronuclei. The eggs leave the body in a 



morula-stage. ' ^ , v 



Strongylus capillarisj— Antonio Pricolo describes under this title 

 a new species, 5-7 mm. in length, 90-100 /x in maximum thickness, 

 which occurs as a parasite in the small intestine of dromedaries, and ap- 

 pears to be associated with haemorrhage, hypersemia, and catarrh of the 

 intestinal mucosa. 



Structure of Male Reproductive Organs in Acanthocephala.|| 

 Willy Bieler has studied the testes, vas deferens, cement glands, and 

 other parts of the male reproductive system in seven species of Acantho- 

 cephala from fishes, and finds that the structure of the cementing appar- 

 atus shows considerable specificity and may be used for systematic 

 purposes. No other part of the system is of use in classification. 



* Centralbl. Bakt. Parasitenk., lxx. (1913) pp. 321-6 (6 figs.). 



t Centralbl. Bakt. Parasitenk., lxxi. (1913) pp. 199-200. 



I Arch. Mikr. Anat., lxxxiii. (1913) 2te Abt., pp. 191-265 (3 pis. and 8 figs.). 



§ Centralbl. Bakt. Parasitenk., lxxi. (1913) pp. 201-2. 



|| Zool. Jahrb., xxxvi. (1913) pp. 525-78 (1 pi. and 15 figs.). 



