WENRICH: SPERMATOGENESIS OF PHRYNOTETTIX MAGNUS. 59 
plished, the two opposing views that have been most widely discussed 
are: — (1) that homologous chromosomes unite side-by-side (para- 
synapsis), or (2) that they unite end-to-end (telosynapsis). The 
adoption of either view, however, involves the very important assump- 
tion that there is a continuity between the chromosomes that appear 
in the earlier divisions and those that conjugate. Doubt has been 
expressed by some writers as to the existence of any such continuity, or 
individuality, of the chromosomes, and the question is regarded as 
one that is still unsettled. Many geneticists, on the other hand, are 
readily inclined to correlate the behavior of the chromosomes in 
maturation with the behavior of Mendelian factors in heredity. And 
in some cases an organization of the individual chromosomes has been 
assumed of such a nature that a definite portion or region of a chromo- 
some is concerned with the transmission of a particular factor. Such 
assumptions call for an analysis of the individual chromosomes to 
determine their inner constitution or architecture. 
The author of the present study has sought to throw light on all 
these problems. That as to how synapsis takes place was the first 
considered; it was taken up from the standpoint of the origin and 
constitution of the chromosomes of the first spermatocytes. Early 
in the work it was found that the only method by which conclusive 
results could be obtained was that of following the history of individual 
chromosomes. Owing to the favorableness of the material, at least 
three chromosome-pairs were found that possessed individual peculiari- 
ties by which they could be recognized through all stages from the 
growth-period to their division in the first spermatocyte mitosis. 
Pursuit of this method naturally led to a consideration of the problem 
of the individuality of the chromosomes, and it was found to be possi- 
ble to recognize one pair of chromosomes at all stages from sperma- 
tognia to spermatids. A further study of chromosome-individuality 
led to the interesting discovery that each chromosome has a definite 
organization, or architecture, which appears at the same stages in all 
the animals studied. 
In the following description, I have not followed the usual method 
of adhering to the chronological sequence of events, but have adopted 
the order in which the problems presented themselves. I believe I 
have been able through a study of this material to demonstrate that 
in Phrynotettix (1) parasynapsis occurs, (2) usually the first matura- 
tion is equational, (3) each chromosome preserves its individuality 
throughout the spermatogenic cell-generations, and (4) at least cer- 
tain chromosomes, and probably all, have a recognizably constant 
organization. 
