m ] GRIGGS— A MITOSIS IN SYNCHYTRIUM 133 



percentage of degenerating small nuclei in every cyst where they 

 occur, either during the period of their formation or later. After 

 nuclear gemmation, however, degeneration of chromatin is relatively 

 small in amount and is almost altogether confined to masses which 

 never organize nuclei. It occurs not in the later portion of the period 

 of gemmation but only during the early portion, when there are few 

 large nuclei in the cysts. In clusters due to heteroschizis, degenera- 

 tion may also occur at later stages, but is infrequent at any time. If, 

 on the other hand, these amitoses are due to pathological conditions 

 affecting the whole parasite, we should expect to find a large number 

 of dying cysts. Fully three-fourths of all the few-nucleate cysts give 

 evidence of amitosis. Of the remainder only a small number show 

 mitoses at this stage. This hypothesis would therefore require that 

 three-fourths of the cysts should degenerate sooner or later. But no 

 -uch thing occurs. Degenerating cysts are seldom found, and the 



degeneration gives no indication of being connected with earlier 

 amitoses. 



The clusters of small nuclei arising from heteroschizis tend to 

 remain close together, and when mitosis is resumed they may form a 

 cluster of small spindles. Fig. 35 shows such a cluster between pro- 

 phase and metaphase, in which the remains of the nuclear membranes 

 are stl11 evi( ient. Below them is the solitary spindle of a large nucleus, 

 whlch ther e are 40-50 in the cyst. Fig. 36 shows three objects 

 T 1 another c yst assembled in one drawing. At a is a similar cluster 

 small spindles; at b is one of the solitary spindles of the larger 

 " .' a11 of whic h in this cyst are in a later phase than the clusters; 

 j C .. 1S a dee P ! y staining mass which has the appearance of a cluster 

 '™ ar to a degenerating. Figs. 37, 38 show similar clusters in ana- 

 gfo Althou g h th e spindle fibers in fig. 38 arc distorted so as to 

 S0 ^ e S °" lewhat th e appearance of a pathological multipolar spindle, 

 SemM thC Spindles are Perfectly normal. The spindles of fig. 37 

 exa^ 1 * ^^ the solitar y spindles of the cyst and are typical 

 t Pes of the peculiar anaphases of this genus. 



quickly 8r ° UPS ° f Sma11 nuclei arisin g b y nuclear gemmation scatter 

 *hich' V ' *° that there is no means of connecting them with the mitoses 

 9topla° CCUr latCr ' The y have the usual relations, however, to the 



Sm and a PPear normal in all microscopic characters. When 



