168 : Recent Literature. __ [February, 
tors are a guarantee of the permanent value of what will bea 
representative American work. It should be widely patronized. 
The illustrations are ample, many indeed from European sources, 
but with many original sketches. The paper and presswork arè 
faultless. The work -is to be issued in six imperial octavo vol- 
umes; Vol. 1 is to be devoted to the lower invertebrates ; Vol. 1 
to arthropods; 11 to the lower vertebrates; 1v to birds; V © 
mammals, and vi to the races of man. 
Davis AND Ricr’s NORTH AMERICAN BATRACHIA AND REPTILA 
FOUND EAST OF THE Mississippi RIVER}—This little book presents — 
us with the best synopsis of our cold-blooded land Vertebrata 
of our region which has yet appeared. The characters of the 
divisions are better drawn than in most American general works, 
though this is not’ very high praise. In fact there is room — 
much improvement in this respect, and it could hardly be ren i 
ical dis 
The authors extend our knowledge of the geographical 
tribution in a good many important points. 
ON THE FORMATION OF THE EGG AND THE BLASTODE P 
Ji 
ee Arsis, by Ludwig Will?—Z. The Forma 
erably from that hitherto described by authors. Huxley, yi i 
and Claus considered that the terminal chamber of "i a 
Aphis differed considerably from the viviparous form, n bs 
the whole arrangement and signification of the elementi f 
in the existence of a yolk passage. Will, however, 5% nd 
in the viviparous Aphis there exists also a yolk passage 
the arrangement of the cells in the interior of the 
quite the same as that in the true females, and ree de 
considers as vitelligenous cells. The wall of the eas 
ovarian tube of the adult is formed of a single layer © 
cells, which not only covers the egg chambe pa 
minal one. Nothing was seen of the structure 
mentioned by former writers on the subject, alth rsion lea 
his investigations one of Zeiss’s homogeneous ker rep, © 
i No. 5 of the Illinois State Laboratory of Ne tural TEP 
b le £ ? ee Af 
Zur Bildung des Eies und des Blastoderm bei den Vea: zi 
Lupwic Witt. Aus den Arbeiten d. zool. zoot. Instituts in 
