GLANDULAR EPITHELIUM AND DIVISION OF NUCLEI. 419 



All these '' fields ^' follow each other consecutively, so that 

 we may say that amongst about 840 nuclei (that is, counting 

 the nuclei of the two lowest layers, each of these two 

 deep), we find IT only, indicative of indirect division. 



In another specimen (of the same tail), prepared inexactly 

 the same manner, we find ; 



la Field 1, two " wreaths ;" two "monasters ;" live "convolutions;" two 

 " baskets." 



In Field 2, two divided, each daughter nucleus "convolution ;" one " mon- 

 aster ;" one divided, each daughter nucleus "basket ;" two " wreaths ;" 

 three " convolutions ;" three " baskets." 



Thus, in these two fields, corresponding, therefore, to about 

 240 nuclei we find 2o forms indicative of indirect division. 

 In connection with this I have to add that I have taken 

 great care not to omit any of those forms ; this is to a cer- 

 tain extent facilitated by the conspicuous appearance pre- 

 sented by the nuclei of this kind. 



As I do not know at what rate the division of the nuclei 

 takes place, and as the thickness of the epidermis is not con- 

 stant in all places, I am not able to use in any, but a very 

 approximate manner, the above numbers, and such as 

 they are, they seem to me, on account of their smallness, 

 to indicate that there must be another method of re- 

 production of nuclei in addition to the indirect one. 

 And we have only to examine carefully the deeper strata 

 of the epidermis to convince ourselves of the presence 

 of nuclei which appear to be in different stages of cleavage. 

 They are oval nuclei, differing as regards their membrane 

 and honeycomb reticulum in no way from the other nuclei 

 of these layers. I have represented in figures 26 — 32, PI. 

 XVIII, the most characteristic forms of nuclei in the various 

 stages of cleavage. They vary in numbers in different parts 

 of a section, and appear to me to be more than merely con- 

 stricted or lobed shapes, such as described by Flemming 

 as being of a temporary nature. Figures 29, 30, and 31 

 seem to me quite convincing. 



I may state here that I have found very numerous nuclei, iii the various 

 stages of cleavage, also in the epithelium lining the neck of the duct of 

 the cutaneous glands. 



It is quite possible that the nuclei undergoing the indirect 

 division in the adult have inherited the power to do this 

 from the ovum, the nuclei of which, as is now well known 

 from numerous observations on different vertebrate and in- 

 vertebrate animals, undergo the indirect mode of division ; 

 it is probable, from Peremeschko's observations, that in the 



