no HUNTER. [Vol. II. 



axis of the cell. In general a very small clear area may be 

 said to surround the central bodies, but it is small compared 

 with the same area in cells of older specimens. A very slight 

 condensation is frequently found, but it is also slight as com- 

 pared with older cells. Rarely, if ever, are astral rays found. 

 In some few cases a decided granular condensation of the archo- 

 plasmic type is found. But in the majority of cases the cen- 

 trosome in the young cell differs from the same structure in 

 the old cell, by existing without protoplasmic rays extending 

 from the central body, frequently without any condensation of 

 cytoplasm about it, and often exists as one or a pair of deeply 

 staining granules, situated in the central part of the cell-body. 

 More than all, it differs in the amount of mechanical influence 

 exerted on the cell structures. In the cells of the young Cyn- 

 thia, where the nucleus is proportionately so much larger than 

 in older cells, we would expect a most decided invagination 

 and excentricity. But such is rarely the case. Exceptionally 

 do we find a nucleus with a decided invagination, and flattened 

 nuclei are rare. The nucleus is, however, always excentric. 

 It is round or ovoid in shape, rarely flattened or pushed into 

 an outpocketing of the cell-body, as is observed in older 

 specimens. These facts can only be explained on the supposi- 

 tion that the centrosome does not exert any decided mechani- 

 cal influence on the cell protoplasm, as is seen by the absence 

 of a disc, sphere, or radiations. Indeed in many small cells the 

 centrosome seems pushed to one side by the larger nucleus. 



The centrosome does not seem to have any fixed position in 

 the cell-body. It was most frequently found between the 

 nucleus and the cell process near the center of the cell. It 

 was also frequently found to lie between the nucleus and that 

 part of the cell most distant from the cell process. It might 

 even lie laterally between the nucleus and the cell membrane. 

 Such positions appeared to be normal. 



The question of the function of the centrosome is of extreme 

 interest, although with our present data it is very far from 

 being solved. Von Lenhosseck has little to say with regard to 

 its probable function, and, with Dehler, seems to consider it a 

 centrosome once actively functioning in division but left over 



