THE ORIGIN OF THE SEX-CELLS OF AMIA AND 
LEPIDOSTEUS 
BENNET M. ALLEN 
From the Department of Anatomy, University of Wisconsin 
TWENTY-SEVEN FIGURES 
INTRODUCTION 
There has been an increasing amount of attention given in the 
last few years to a study of the origin and migration of the sex- 
cells of the vertebrates. The number of forms in which this 
subject has been studied is being constantly extended. While 
much conclusive work has been done, upon the history of these 
cells in the elasmobranchs, and an equal amount in tracing them 
in the teleosts, up to this time, they have never been studied in 
the ganoids. This work was begun over two years ago, and was 
reported at the 1908 meeting of the Association of American 
Anatomists in New York. (Allen, ’09.) 
The material for the present work is obtainable in great plenty 
within less than half a mile of the grounds of the University of 
Wisconsin. Since the breeding habits of these two fishes have 
been thoroughly treated by other writers, it is not necessary to 
redescribe them. Telleyesniczky’s bichromate-acetic fluid and 
Zenker’s fluid have been used as fixing agents and have proved in 
every way satisfactory. One secret of obtaining good sections 
is to secure most thorough infiltration by placing the material 
in a solution of paraffine in turpentine. While turpentine has a 
bad reputation, no deleterious effects were noted in the course 
of the work. Paraffine sections were made without difficulty 
7u and 10u thick, and were stained, for the most part, in haem- 
alum and orange G. Heidenhain’s iron haematoxylin stain was 
JOURNAL OF MORPHOLOGY, VOL. 22, NO. 1 
MARCH, 1911 
