CH.ETOPODA — acanthocephala. 479 
clieetoiis annelid Limnodrilus (Q. J. Micr. Sci. July 1870, and Ann. N. H. 
February 1871). Brandt’s memoir is finely illustrated. 
9. Balbiani finds that the egg of Strongylus gigas commences to develop 
in the uterus of the female, but soon stops, further development occurring 
after expulsion from the body of the host and in contact with water or moist 
earth. Five or six months elapse in winter between this period and the 
appearance of the embryo. The embryo can remain a year at least within 
the egg without perishing. If pressed out into pure water it is destroyed ; 
it can only live in albuminous fluids : desiccation destroys it. A temporary 
host, at present unknown, is (the author concludes) occupied by the develop- 
ing embryo, whence it migrates into its final host. 
10. Marion describes, in ninety pages, illustrated with eleven plates, a 
number of non-parasitic marine Nematoids. Twenty-two supposed new 
species are described; and a special portion of the work is devoted to 
anatomical considerations. It is exceedingly remarkable that the author 
makes no reference whatever to the elaborate papers by Dr. Bastian on the 
very same subject, published in the Linnean Society’s Transactions and the 
riiilosophical Transactions of the .Royal Society. French naturalists cannot 
expect their work to secure respect when they ignore so completely the 
work of others. 
11. ZuRN investigates the question of the occurrence of Trichina as a 
parasite in insects. He allowed flies to lay their eggs in some trichinized 
pig’s flesh, and after examining 160 of the maggots found no indication 
whatever of their being affected with Trichince. He suggests that cases of 
viviparous reproduction, such as that of the Cecidomyia-Xoxyi^^ may have 
given rise to the notion that insects are liable to Trichiniasis. 
12. Metschnikoff discusses some of the forms described by Greef in a 
recent paper, which he has also met with in the Mediterranean. He con- 
siders that Greef has mistaken the testes of Echinoderes for ovaries, and the 
spermatozoa for embryos. Ziirn, of Jena, has recently shown that in the 
nematoid Spiroptera circinnata the converse mistake had been made by 
Muller, of Vienna, the young embryos of this viviparous form having been 
taken by him for spermatozoids. 
13. The Filaria was found in the pericardium of H, hennettii. Its anatomy 
is sketched. 
14. Schneider took the eggs of the Echinorhynchus gigas from the pig, fed 
the larva of Melolontha vulgaris with them, and readily succeeded in watching 
the development of the eggs. With the larva of Tenehrio molitor and with 
Asellus aquaticus he did not succeed. He found the embryo of Echino- 
rhynchus gigas easier to observe than the species which have been studied by 
Leuckart and by Greef, because of its larger size. The difficulty of under- 
standing the Echinorhynchi lies, he considers, not in a want of knowledge as 
to them themselves, but in the absence of once-existing intermediate forms. 
Their structure may be best explained by regarding them as double animals, 
the proboscis-apparatus being one animal and the sexual apparatus another, 
whilst the body-wall is common : both units are mouthless. The kind of 
aggregation seen in the Bryozoa is parallel to this. Such a view of the 
morphology of the Echinorhynchi is favoured by their developmental history, - 
of which Schneider promises shortly a fuller account. 
16. Van Beneden (senior) extends his classification of parasites, giving 
