44 J- T. PATTERSON AND LELIA T. PORTER. 



chromatin (Fig. 9). This abortive division is homologous to the 

 first spermatocyte division which normally occurs in other forms, 

 and the two unequal cells thus produced are to be regarded as 

 equivalent to second spermatocytes. 



The small non-nucleated cell, or mass of cytoplasm, soon 

 degenerates, although in some cases it may persist until the 

 second maturation division is well advanced. All stages in the 

 disintegration of the mass are to be seen in a single cyst. The 

 fragmenting masses lie in the interstices of the dividing second 

 spermatocytes. 



The most interesting point to be noted in connection with this 

 abortive maturation division is the fact that nothing comparable 

 to a synapsis of chromosomes occurs. The absence of this 

 phenomenon, which is universal in the spermatogenesis of males 

 arising from fertilized eggs, is undoubtedly due to the fact that 

 the unmatured, male germ cell of Paracopidosomopsis possesses 

 but the haploid number of chromosomes. The function of the 

 first maturation division is to bring about a reduction from the 

 diploid to the haploid number of chromosomes; but the males 

 of this species, by virtue of their origin from matured, but 

 unfertilized eggs, already possess the half number, and conse- 

 quently, the first maturation results in a feeble or abortive 

 attempt at a division. 



SECOND MATURATION DIVISION. 



Throughout the entire period occupied by the first matura- 

 tion, the nuclear membrane remains intact (Figs. 5-9). At the 

 end of this period the incomplete intranuclear spindle disappears, 

 as do also the fibers which radiate from the centrosome included 

 in the small cytoplasmic mass (Fig. 9). On the contrary, the 

 aster, which lies at the lower side of the nucleus in the true 

 second spermatocyte, persists. It is highly probable that this 

 aster, by a division of its centrosome, gives rise to the second 

 maturation spindle, as is the case in the European hornet. 



In the brief interim between the first and second maturations, 

 the nucleus enters a rest stage. The chromatin recedes to that 

 side of the nucleus lying farthest from the cytoplasmic bud, and 

 becomes so massed that it is impossible longer to distinguish 



