556 



Theophilus s. Painter, 



Part IV. Discussion. 



1. Irregularities. 



Under the present heading- I wish to call attention to some 

 irregularity which may be shown by the autosomes during the 

 maturation divisions. The usual behavior of the autosomes, as shown 

 by many of the figures, is, for these bodies to divide after the 

 accessory chromosome had gone to one pole. It may happen, however, 

 that one or two of these bodies divide earlj^, as shown in Fig. 38. 

 At first sight this is apt to confuse the observer and no doubt some 

 of the earlier incorrect observations on the accessory chromosome 

 were due to such figures as shown in 38. This is particularly true 

 of the specimen of Lycosa communis. Here very frequently one of the 

 bivalent autosomes divides before the accessory goes to one pole. 

 A case of this is also shown in Fig. 54, for the tufted variety of 

 Maevia vittata. 



TUFTED MALE 



Diaf^rani III. 



This irregularity seems to be of no consequence and does not 

 affect, as far as I have been able to determine, the ultimate 

 distribution of tiie autosomes. I have seen no evidence, with ex- 

 ception of the peculiar planosomes, that the chromosome number 

 varies among the diff'erent individuals of a species. 



