No. 415.] REVIEWS OF RECENT LITERATURE. 599 
In the Journal of the College of Science, in the Imperial University 
of Tokyo, Dr. S. Hatta of the College of Peers has an important 
memoir on the development of “ Pronephros and Segmental Duct 
in the Lamprey.” It is a worthy member of the series of admirable 
papers setting forth the original investigations of the students and 
associates of Professors Mitsukuri, Watase, and Iijima — one of 
the most hopeful phases of the development of New Japan. 
Notes. — The anatomy of the wings of the thrushes belonging to 
the genus Micropus has been very fully worked out by Buri (Jena 
Zeitschr., Bd. XXXIII, pp. 361-610). The account includes a full 
description of the brachial plexus and of the muscles of the wing, 
and is based on a broad comparative study of the subject. Unfor- 
tunately the general results are meagre and pertain chiefly to minor 
questions in the taxonomy of this group of birds. As an illustrated 
record of the comparative anatomy of the parts investigated, Buri's 
contribution is a praiseworthy effort. 
The number of ants in a hill has been variously estimated. Forel 
made an indirect calculation for a hill of medium size of Formica 
pratensis and arrived at the conclusion that it contained 114,000 
ants. The largest hills he thought might contain as many as 
500,000. In these conclusions he was supported by Lubbock. Yung 
(Archives Zoól. Expérim. et Générale, 3 Sér, Tome VII, pp. xxxiii- 
XXXv, 1900), however, has made actual counts of all the inhabitants 
in several isolated hills of Formica rufa. He has found the numbers 
to vary between 19,933 and 93,694 and not to be proportional to the 
size of the hill. He believes that the previous estimates have been 
exaggerated. : 
The New York State Entomological Field Station, which held its 
first session at Saranac Inn last summer, will remove to Ithaca for 
the coming season. Professor James G. Needham of Lake Forest 
University will continue in charge of the work. The report of the 
first session, which is expected to issue shortly, will contain among 
other things extensive contributions to the knowledge of the life 
histories of aquatic insects, especially dragon flies, may flies, and 
caddis flies, and a few very interesting forms of Neuroptera and 
Diptera. 
Although the medullary substance of the brains of most verte- 
brates has been rather fully studied, this portion of the ungulate 
brain, for some unknown reason, has received very little attention. 
