Katharine Foot and E. C. Strobell 281 
This dimorphism of the spermatozoa first observed in Pyrrocoris by 
Henking, 91, has received such wide support from later observers in a 
large variety of forms that it is with much hesitation we question its 
occurrence in a form so well known as Anasa. Realizing the futility of 
disputing the interpretations of the noted investigators of this form with 
the inadequate demonstration furnished by drawings, we have illustrated 
our evidence with one hundred and six photographs of our preparations 
—these being selected from a series of three hundred and thirty—these 
in turn being chosen from nearly a thousand cells indexed as sufficiently 
clear to be photographed. These examples were selected from the cells 
of more than fifty smear preparations. We have studied also sections 
of the testes and made a few photographs of these sectioned cells in addi- 
tion to those above mentioned, but the photographs of Plates I to III 
are of our smear preparations. This data covers a relatively limited 
field of the development, 7. e., the spermatogonial chromosomes and from 
the growth period of the first spermatocyte to the telophase of the second 
spindle inclusive. These stages have been shown by Montgomery and 
Wilson in a few camera lucida drawings and this evidence we will later 
compare in detail with our photographs. In their investigations, how- 
ever, they have covered a much broader field, having studied a large 
number of forms. We fully appreciate some of the advantages claimed 
for a broad comparative method of work, though we can scarcely 
agree with Montgomery, 06, when he says (in reference to another point 
under discussion), “‘no one has a right to express doubt . . . . who has 
not made broad comparative observations of his own,” p. 152. In this 
connection it is interesting to question just how far we may safely follow 
a broad comparative method without sacrificing that painstaking atten- 
tion to details acknowledged as indispensable in all lines of scientific 
work. 
We believe that our preparations demonstrate the following points: 
First, that there are twenty-two spermatogonial chromosomes. 
Second, that none of these chromosomes retain their morphological 
individuality throughout the growth period—neither the microchromo- 
somes as claimed by Paulmier and Montgomery, nor an odd chromosome 
identified by Wilson, and later by Montgomery, as a_heterotropic 
chromosome. 
Third, that in the early prophase of our preparations the so-called odd 
(heterotropic) chromosome of Wilson and Montgomery (t. e., the eccen- 
tric chromosome of the later prophases, or metaphase), resembles in no 
