1896.) ` “ Mushroom Bodies” of the Hexapod Brain. 643 
which are more or less arbitrary and unsatisfactory, and all 
of which are liable to be set aside at any time. I have heré 
adopted Migula’s system” which seems to me very convenient, 
and on the whole the most satisfactory of any that has yet 
appeared. 
Before proceeding to the body of this review it only remains 
to say that every effort has been made to deal impartially with 
the material in hand, and to present the essential ideas of the 
writers as concisely and accurately as possible. To this end 
the original papers have been consulted in every instance, 
unless otherwise stated in the text. So much vexation over 
wrong references has been experienced in time past by the 
writer that he has himself been at special pains to give full and 
accurate citations. It is to be hoped, therefore, that the read- 
er will have no difficulty in finding the original papers. An 
endeavor has also been made to bring the subject fully up to 
date but it is quite likely that some worthy papers may have 
been overlooked, owing to the many languages and the ever 
increasing number of places of publication. 
THE MEANING AND STRUCTURE OF THE 
SO-CALLED “MUSHROOM BODIES” OF 
THE HEXAPOD BRAIN. 
By F. C. Kenyon, Pua. D.' 
In looking at a series of sections of the brain of a hexapod, 
especially of a hymenopteron, the most notable structures are 
two pairs, one to each side, of large cup-shaped bodies of “ Punkt 
substanz,” or, what in the light of our present knowledge of 
nerve structure is better denominated fibrillar substance. 
Each of these cups is filled to overflowing with cells having 
large nuclei and very little cytoplasm. From the under surface 
? Migula: Schizophyta : (22) Schizomycetes. Die Natuerlichen Pflanienfami- 
lien (Engler u. Prantl). I Teil. 1 Abt. a, Lief. 129. 8vo. p. 44, Leipzig, 1896. 
bc is the forerunner of a larger work soon to be published by Gustav Fischer, 
l Tick University, Mass. 
