I5O O. C. GLASER. 



of these accessory organs amitosis was observed, and in all the 

 same extra-nuclear signs of activity which characterize the cells 

 of the primary kidneys. 



Function. - - Between the two extremes of development which 

 I have described the nuclei of the external kidneys divide ami- 

 totically and the cells become polynucleated. The nuclei are 

 large, granular, very irregular in outline, and each one has at 

 least one nucleolus surrounded by a clear area. In addition the 

 cells are characterized by their thick boundaries and the highly 

 vacuolated condition of their contents. 



On a former occasion ('04) I showed how the vacuoles in the 

 cells might be traced to the halos surrounding the nucleoli, but 

 the figures intended to illustrate this are unsatisfactory since 

 certain features which I hoped would not appear so unnaturally 

 prominent when reduced to one half are over emphasized. More 

 satisfactory figures will be found in my later paper ('05). The 

 vacuoles which in some cases can be traced directly to the extra- 

 nucleolar halo, in others to the nucleus from which I have seen 

 them escaping, certainly suggest a high state of metabolic activity. 



In the summer of 1903, with a view to determining the nature 

 of the activities in the external kidneys, I removed several hun- 

 dred, extracted them in chloroform water and asked my father to 

 make a careful analysis of the extract. The details of this 

 analysis have already been published ('05) but as all the decimal 

 points were omitted by a careless printer, I republish the follow- 

 ing corrected summary. One liter of the aqueous extract of the 

 external kidneys contained 



N as albumen, .1242 



N as free ammonia, .0099 



N as urea or homologues, -2163 



Total N, -354 



My interpretation of the above analysis was that the external 

 kidneys excreted waste products, but a reconsideration of the 

 evidence, shows that it can become decisive only after corre- 

 sponding analyses of extracts of other tissues have been made. 

 Regardless of the value of the chemical evidence, which is cer- 

 tainly not negative, I still think that all the morphological results 

 point to the probability that the external kidneys are excretory 



organs. 



