160 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
years ago * * * § on the two kinds of unfertilised ova found in this worm. 
Some never pass beyond the long conical form which is normal at the 
time of separation from the rachis. As they are pushed forward in the 
uterus, their nucleus becomes multinucleolar. On the other hand, there 
is a second kind which change in form towards that of the fertilised ova ; 
their nucleus begins to exhibit mitotic changes, but no expulsion of polar 
bodies is effected ; they have a delicate primary vitelline membrane, 
which does not thicken as in the fertilised eggs, nor is a secondary 
vitelline membrane formed. In this second kind of unfertilised ovum, 
with which alone 0. Hertwig dealt in his discussion of the matter 
(cf. supra), there is an egg-envelope formed by the uterine epithelium. 
(Esophagus of Nematodes. f — Herr L. A. Jagerskiold has made a 
minute study of the oesophageal region, especially in Strongylus armatus 
and Dochmius duodenalis. In parasitic forms which feed on more or less 
prepared foods, the bulbous portion and, its glands may be more or^less 
degenerate ; and a consideration of this lends some general interest to 
the author’s histological descriptions. He also describes J Cliordodes 
Kallstenii , a new Gordiid from Kameroon. 
Vitality of Parasitic Nematodes outside their Host.§ — Herr J. 
Dewitz removed some Nematodes from the connective tissue of the 
mackerel, and placed them in a watch-glass with a piece of sponge 
damped with salt water and cod-liver oil. They flourished well for a 
time, but most died in three months. The necessity of contact with a 
solid body is emphasised. 
An Undetermined Parasite of the 0x.|| — A. Borgeaud describes the 
occurrence of nodules, like tuberculosis nodules, on the course of the 
blood-vessels in the wall of the small intestine of “ charolaise ” cattle. 
The nodules vary in size from that of a grain of wheat to that of a cherry- 
stone ; they have a resistant capsule, and the contents are caseous, and 
sometimes calcareous. The smallest sometimes contain larval nematodes 
up to 3 mm. in length ; and although no identification can be made with- 
out finding the adults, the shape of the mouth bears a resemblance to 
that of Sclerostomum hypostomum, near which the form in question should 
probably be placed. It does not seem to do much harm. 
Nematodes of Birds. — Herr W. Volz makes a statistical report on 
the occurrence of Nematodes in birds. He gives a list of 24 forms, 
noting their hosts and the parts infected. Then follows a list of 32 
birds examined with their respective parasites. The frequency of occur- 
rence in the various organs is also noted. 
Platyfielminthes. 
Cestodes of Monotremes and Marsupials.** — Herr F. Zschokke de- 
scribes Bertia edulis sp. n. and B. sarasinorum sp. n., both from PJialangcr 
* Arch. Mikr. Anat., xxiii. pp. 174-6. 
t Bihang k. Svensk. Yetensk. Akad. Handl., xxiii. (1898) Afd. 4, No. 5 (26 pp.,. 
2 pis.). J Tom. cit., No. 7 (10 pp., 1 pi.). 
§ Zool. Anzeig., xxii. (1899) pp. 91-2. 
|| CR. Soc. Vaudoise Sci. Nat., in Arch. Sci. Phys. et Nat., vi. (1898) pp. 648-9. 
1 Rev. Suisse Zool., vi. (1899) pp. 189-98. 
** Zeitschr. wiss. Zool., lxv. (1899) pp. 404-45 (2 pis.). 
