1880. ] Recent Literature. 585 
ually become in part the abdominal opening of the Miillerian 
duct, and which correspond with the head-kidney, or “ vorniere”. 
of German authors; they also conclude that the Miillerian duct 
does not develop entirely independently of the Wolffian duct ; and 
finally the authors discuss certain rectifications in the views of the 
homologies of the parts of the excretory system in birds, necessi- 
tated by the results of their investigations. 
In the second paper Mr. Balfour traces the early development of 
the lizards, and discusses the nature and relations of the primitive 
streak. He also shows in the third paper that the nervous cords 
‚of Peripatus are minutely ganglionated, and are not simple ner- 
vous threads as heretofore supposed. 
Messrs. Scott and Osborn’s paper on the early develop- 
ment of the common newt of England we have elsewhere noticed. 
The fifth paper is by Mr. Adam Sedgwick, on the development of 
the kidney in its relation to the Wolffian body in the chick. 
Although considerable good work has been done on the embry- 
ology of the spiders, Mr. Balfour has worked out additional points 
of much interest in his paper on the development of the Araneina. 
Among these he has proved that the supra-cesophageal ganglion 
of the adult is the result of the fusion of what in the embryo are 
two separate ganglia, and he thus effectually settles the ques- 
tion as to whether the first pair of appendages, the mandibles, 
represent the antenne of the insects and myriopods, since he 
demonstrates that the nerves to these appendages are sent from 
what is originally the second pair of nervous ganglia, thus show- 
as that the antennz are morphologically as well as functionally 
absent, 
€ view at one time prevalent, that the Arachnida are- as 
nearly related to the Crustacea as to the insect, is not sustained 
” 
insisted upon by others, that the Arachnida and insects (Hexa- 
Poda) as well as myriopods belong to a class, [Insecta or Trach- 
fata, as opposed to the. Crustacea or gill-bearing Arthropods, 
which may, with Gegenbaur, be called Branchiata. 
_ The seventh and last paper, by Mr. Adam Sedgwick, treats of 
the development of the structure known as the “ glomerulus of 
the head-kidney ” in the chick. This has been found to be “ noth- 
mg more than a series of glomeruli of primary Malphigian 
VOL. XIV.—NO, vir, 38 
