QUARTERLY CHRONICLE. 275 
delicate bodies by the chemical reagents employed. The 
cells should be as much as possible isolated, and this can be 
done by judicious maceration in weak solutions of chromic 
acid 35, a5, 745 grain to the ounce of water, or of +, 1, 2 
grains of chromate of potass. 
Acknowledging the perfect correctness of Dr. Beale’s and of 
Deiters’s figures and descriptions of the fibrillated appearance 
of the ganglion cells, he observes that this appearance, which 
Dr. Beale ascribes to the existence of peculiar currents per- 
vading the cell during life, and which is described by From- 
mann as indicating the composition of the cell to be mainly 
of a plexus of fibrils proceeding from the nucleus and 
nucleolus, the author regards as altogether artificial, and to 
be due in part to corrugation and in part to coagulation of 
the cell substance. 
6. “ On the male of Psyche helix (Helicinella) together 
with Remarks on the Parthenogenesis of the Psychide,”’ by 
Prof. C. Claus, of Marburg.—The object of this paper, 
which contains a very compendious history and literature 
of the subject of parthenogenesis in the Tineide and 
Bombycide, is to prove that the male of Psyche helix 
does really exist, and to give a description of it, which 
is illustrated by beautiful figures. ‘The author consequently 
concludes that even in that species,—in which, as is well 
known, parthenogenesis was supposed, more than in any 
other, to be the only mode of reproduction,—the concurrence 
of the sexes, at any rate occasionally, intervenes. 
7. ‘On the Formation, Structure, and Systematic Value of 
the Egg-shell in Birds,” by Dr. R. ,Blasius.—This memoir 
was prepared in accordance with a wish expressed by the 
author’s father, that Landois’ ‘ Histological Researches on 
the Eggs of various species of Birds’ might be extended to 
other species, with the view of ascertaining the systematic or 
classificatory value afforded in the minute structure of the 
shell. 
In proceeding with this task, the author commences with 
the minute structure of the different parts of the oviduct, 
which is preceded by a copious historical and critical account 
of previous writings on the subject. He then gives an ac- 
count of the histology and development of the egg-shell in 
the fowl and pigeon, concluding with the systematic value of 
the results. 
With respect to the third subject, or to the value of the 
systematic characters derivable from the microscopic investi- 
gation of the shell,—to which, as is well known, M. Landois 
attached very great importance,—Dr. R. Blasius remarks that 
