ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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oesophageal plate, and the development of the final oesophagus from the 
elements of the head blastoderm. But as the author allows, his results 
are not as yet altogether conclusive. 
Gilson’s “ Musculo-Glandular Cells.” * * * § — Dr. J. Ogneff has studied 
the epithelium of the somatopleure in Owenia, in which Prof. Gilson 
described the existence of musculo-glandular cells, — a double differ- 
entiation in one element. But Ogneff has not been able to confirm this 
in the least ; the muscular layer of the body-wall is quite distinct from 
the peritoneal elements. He blames the paraffin-method for what he 
regards as Gilson’s mistake. 
Vermiculus limosus.f — S. Hatai describes this new species, which 
is very common in the muddy gutters and ditches of Tokyo, occur- 
ring together with Limnodrilus, Tubifex, and other Limicolse. It creeps 
about on the lower surface of fallen leaves and other objects, and rarely 
buries the anterior part of its body in the mud, as do most of the Limi- 
colse ; nor does it swing the posterior part of its body like Tubifex. 
The general colour is milky-white, and the intersegmental lines are 
blood-red. It is very sluggish, and on being pinched, never executes 
writhing contractions, but simply retracts its body. These peculiarities 
serve to distinguish this species from its neighbours in the mud. It 
differs from the other known species of the genus — Vermiculus pilosus 
Goodrich — in having no clitellum, no oviduct, a single sperm-sac, cilia- 
like processes not uniformly distributed, and in some other points. 
Black Oligochsete from Glaciers of Alaska.^ — Prof. C. Emery has 
a brief note on this (unnamed) form, which seems to represent a new 
genus of Enchytraeidm. Its most remarkable character is the black 
pigmentation of the epidermis, which appears to be unique, though there 
are some undescribcd alpine forms of dark colour. 
Glycera and Goniada. § — Ivar Arwidsson communicates some 
faunistic notes on Glycera goesi Malmgren, and a comparative study of 
the species of Glycera and Goniada , especially as regards the vascular 
system and its simplification in the course of development. 
N ematohelminthe s . 
Unfertilised fOvai’of Ascaris megalocephala. — Prof. 0. Hertwig || 
has observed the behaviour of uterine ova in two specimens of Ascaris 
megalocephala which showed no trace of spermatozoa. At first the eggs 
behaved as if they had been fertilised ; the germinal vesicle began to 
break up and to form a characteristic tetrad group of chromosomes. 
This group moved to the periphery, and took up the position of a 
directive spindle ; but no well-defined spindle was formed. Meanwhile 
a firm vitelline membrane was formed, which remained closely apposed 
to the egg. No signs of parthenogenesis were observed. 
Prof. M. Nussbaum recalls the observations which he made some 
* Biol. Centralbl., xix. (1899) pp. 136-41. 
f Annot. Zool. Japon., ii. (1898) pp. 103-11 (5 figs.). 
X Arch. Sci. Phys. et Nat., vi. (1898) pp. 506-7. 
§ Bihang k. Svensk. Vetensk. Akad. Handl., xxiii. (1898) No. 6 (30 pp., 2 pis.). 
|| SB. Akad. Wiss. Berlin, 1898, pp. 673-5 (3 figs.). 
^ Zool. Anzeig., xxii. (1899) pp. 77-9. 
