58 H. H. NEWMAN. 



resting state and has every appearance of undergoing healthy 

 changes which should culminate in cell division by mitosis. It 

 is impossible to state positively that such a nucleus has regressed 

 from the spindle condition shown in text-figure 2, but that 

 such is the case seems at present to be a reasonable conjecture. 

 In eggs of this sort there is a characteristic zone of activity in 

 the cytoplasm at a short distance from the nuclear membrane 

 which may indicate active interchanges between nucleus and 

 cytoplasm. The chromatin is in the form of a series of beaded 

 threads resembling a spireme and therefore may be interpreted 

 as in a very early prophase of the first cleavage. Soon the 

 chromosomes begin to condense and the typical appearances of 

 later prophases pass over into unmistakable mitotic figures like 

 that shown in Fig. 4, which can be interpreted in no other way 

 than as cleavage spindles. The so-called cleavage mitoses of 

 other writers on this subject have been interpreted by opponents 

 as belated maturation spindles which have been displaced and 

 distorted by the abnormal conditions of atresia; but such an 

 interpretation of the figures here described would seem very far- 

 fetched in view of the fact that these spindles are so radically 

 different from the naked, insulated spindles of maturation. I 

 have never seen a vestige of astral radiations in a polar spindle, 

 while the radiations in a number of such cases as that shown in 

 Fig. 4 are as obvious and as extensive as those which I have 

 observed in the cleaving eggs of annelids and other favorable 

 material, and far clearer than similar appearances in fish eggs or 

 other less favorable material. The spindles are frequently 

 abnormal in form, being not uncommonly tri- or multipolar; 

 and sometimes the poles are ill defined, as in Fig. 4, but the 

 radiations are always very distinct. When the figure is multi- 

 polar the chromatin distribution is very irregular and nests of 

 nuclei (like those show r n in Fig. 12) are produced without any 

 division of the cytoplasm. It is very common to find such 

 multinucleate but unicellular eggs and I am inclined to attribute 

 their existence to such irregular mitoses as that just mentioned. 

 Certain considerations lead me to venture a conjecture as to the 

 mode of origin of these multipolar spindles. It is not uncommon 

 to find in ovocy tes of the type shown in text-figure 2 various steps 



