m 'clung: spermatocyte divisions of the locustid.e. 205 



where the Orthoptera are least valuable in demonstrating chro- 

 mosomal relations the Hemiptera and Peripatus are most con- 

 vincing. I refer here to the derivation of the first spermatocyte 

 chromosomes from the chromatin of the spermatogonia. He 

 claims to have observed the union by pairs of the secondary 

 spermatogonial chromosomes during the anaphase (his synap- 

 sis) so clearly as to be positive of this fusion. I hope this may 

 be verified, for it offers a logical explanation of the process of 

 reduction, and is a confirmation of what has previously been 

 assumed true without sufficient basis in observed fact, as was 

 suggested in my paper on Hippiscus. This, if established, 

 would also be a strong support of the theory relating to the 

 constancy of the chromosomes. If this true synapsis is accom- 

 plished at this time, however, it must be noted that it occurs 

 during the last phase of the final spermatogonial mitosis, and 

 is not an act of the spermatocyte prophase. But as to the exact 

 location of this point no contention need be made, for it is con- 

 ceivable that the time of its occurrence might vary considerably 

 without affecting the essential nature of the process. 



With regard to such an origin of the first spermatocyte chro- 

 mosomes, there is an important difference to be noted between 

 the earlier and later work of Montgomery, and one which he 

 fails to mention. In his paper (12) upon Euchistus he states 

 the matter as follows: "But in the post synapsis we do not 

 find seven chromosomes, the definitive number present in the 

 spermatocyte divisions, but a smaller number ; hence, in the 

 synapsis the true (i. e., exactly half) reduction of the chromo- 

 somes does not take place, but the number is reduced to less 

 than one-half." This statement is based, he says, upon a most 

 careful and painstaking enumeration of the chromatic segments 

 in a number of nuclei, and is unhesitatingly declared correct. 



In his later paper, on the contrary, he is just as positive that 

 the definitive reduction is here accomplished, for he says : 

 "Since then I have been able to demonstrate that this numer- 

 ical reduction is effected in the synapsis by the union into seven 

 pairs of the fourteen chromosomes, each of the seven bivalent 

 chromosomes ( pairs ) being composed of two univalent chro- 

 mosomes joined end to end." This statement is made without 

 adducing any specific proof, as was formerly done. By what 

 means we are to reconcile these diametrically opposite state- 



