164 LIFE AND DEATH. 



certain, sooner or later, to disappear. There is there- 

 fore no real cell without a nucleus, any more than 

 there is a nucleus without a cell. The exceptions to 

 this law are only apparent. Histologists have 

 examined them one by one, and have shown their 

 purely specious character. We may therefore lay 

 aside, subject to possible appeal from this decision, 

 organisms such as Haeckel's monera and the problem 

 of finding out if bacteria really have a nucleus. The 

 very great, if not the absolute generality of the 

 nuclear body, must be admitted. 



It hence follows that there is a nuclear protoplasm 

 and a nuclear juice, just as we have seen that there is a 

 protoplasm and a cellular juice. What was just said of 

 the one may now be repeated of the other, and perhaps 

 with even more emphasis. The nuclear protoplasm 

 is a filamentary mass sometimes formed of a single 

 mitome or cord, folded over on itself and capable of 

 being unrolled. The mitome in its turn is a string 

 of microsomes united by the cement of the linin. 

 These are the same constituent elements as before, 

 and the language of science distinguishes them one 

 from the other by a prefix to their name of the words 

 cyto or karyo, which in Greek signify cell and nucleus, 

 according as they belong to one or the other of these 

 organs. These are mere matters of nomenclature, 

 but we know that in the descriptive sciences such 

 matters are not of minor importance. 



We have just indicated that in a state of repose, — 

 that is to say, under ordinary conditions, — the structure 

 of a nucleus reproduces clearly the structure of the 

 cellular protoplasm which surrounds it. The nuclear 

 essence is best separated from the spongioplasm. 

 It takes more clearly the form of a filamentary 



