AMONG SIMPLE SARCODE ORGANISMS. 411 



also generally increased, but not necessarily in the same ratio as 

 that of the chambers. In some of the chambers there occurred 

 only one nucleus, while others contained several. 



The nucleus appears to enclose a nucleolus and to be invested 

 hy a membrane, thus corresponding in its structure with that 

 of the freshwater Monothalamian Ehizopods. 



Similar results followed the employment of the same method of 

 investigation in Botalia and in Textillaria, in both of which 

 genera Hertwig succeeded in demonstrating the presence of 

 nuclei. 



Schulze had already seen what he regarded as a nucleus with 

 nucleolus in one of the Foraminifera, QuinquelocuUna fusca, 

 Brady* ; and he now finds an undoubted nucleus lying near the 

 posterior end of the shell in Untosolenia glohosa, one of the marine 

 monothalamian rhizopods belonging to the family of the Lagenidse. 



In the very abundant polythalamian rhizopod JBolystomella 

 striatopunctata he has also demonstrated the presence of a nu- 

 cleus, and has carefully followed out its relations. 



The nucleus here has a manifest thick outer membrane with 

 clear contents in which were several strongly refringent roundish 

 bodies. Usually only one such nucleus was to be found in each 

 Polystomella, and then always near the middle of the series of 

 chambers ; but occasionally two or three occurred each in a separate 

 chamber. 



Prom the dependence of the position of the nucleus on the en- 

 tire number of the chambers, it is obvious that it must be conti- 

 nually migrating from one chamber to another through the canals 

 of communication. Indeed the nucleus may frequently be seen 

 stiU engaged in one of the canals between two neighbouring 

 chambers, so as to be partly in one and partly in the other. 



From the fact of the many-chambered Folystomella containing, 

 as a rule, only one nucleus, we should be justified in assigning to 

 it the morphological value of a single cell ; and even in those 

 cases in which in this and other Foraminifera several nuclei have 

 been seen, this multinucleate condition cannot be regarded as 

 indicating a multicellular structure of the organism. It is pro- 

 bably connected with reproduction ; and an observation of Hertwig 

 on Hotalia contributes some additional facts to our knowledge of 

 the reproduction of the Foraminifera, hitherto observed in but 

 very few instances. 



* Arch. 1'. mikr. Anat. vol. xi. 



