62 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
is evidence that the ordinary chromosomes have individual morpho- 
logical characteristics. 
In striking contrast to the results of McClung and Sutton, Mont- 
gomery (:05) concluded that in Syrbula (an acridid) the first matura- 
tion division instead of the second, is the reducing division. He 
also found that the accessory chromosome of the spermatocyte is 
represented in the spermatogonia by two chromosomes, and that it 
divides during the maturation divisions in the same way as the other 
chromosomes. Farmer and Moore (:05) also held that in the cock- 
roach (Periplaneta) the first maturation division is the reducing divi- 
sion. Moore and Robinson (:05) have reached the conclusion that 
the so called accessory chromosome in Periplaneta is nothing more 
than a true nucleolus, and that it disappears before the first matura- 
tion division. On the other hand Stevens (:05") has found that in 
Blatella the accessory chromosome has practically the same history as 
that described by McClung, Sutton, and de Sinéty for other Orthop- 
tera. However, in Stenopelmatus (the California sand cricket) she 
found a structure in the primary spermatocyte which, in position and 
form, resembled the accessory chromosome, but differed from it in 
mode of origin. During the first maturation division this element 
passes bodily into one of the daughter cells, where it degenerates 
before the second division. 
Some very surprising results have been reached by McClung (:05), 
who believes that in several species of the Acrididae and in one locus- 
tid (Anabrus) there is, even in the spermatogonia, a bivalent chromo- 
some to the end of which the accessory chromosome becomes attached 
during the prophase of the first spermatocyte division. In one species 
‘the chromatic. element formed by the union of a bivalent and the 
accessory chromosomes unites with another bivalent chromosome 
so that there is a single element composed of two tetrads and the 
accessory chromosome. During the first maturation division one 
entire tetrad and the accessory pass into one, the other tetrad into the 
other daughter cell. 
Recently Otte (:06) has arrived at results diametrically opposed to 
those of most of the preceding investigators. He finds that in the 
spermatogonia of Locusta the chromosomes remain perfectly distinet 
during the resting stage, each chromosome lying in a separate vesicle. 
During the early growth stages of the primary spermatocytes the 
chromosomes are in the form of chromatic filaments, which conjugate, 
side by side, in pairs. ‘The bivalent chromosomes thus formed are 
divided transversely in both maturation divisions, there being no 
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