<^23. 



INFUSORIA AND RHIZOPODA. 8S 



It is not rare that a variable number of these round nuclei, arranged in 

 a row, traverse the body in a tortuous manner. This is so in Stellt or 

 coendeus and poly mo7-phus, in SpirostomuTn amhii^iaim, and in Tradtelhis 

 vioniliger. In man}' instances the nucleus has the form of an elongated 

 band, which is slightly curved in Vorticella convallaria, Epistylis leucoa, 

 Prorodon niveus- and B^crsaria truncatella. In Stentor RcBselii, it is 

 spiral, and in Enplotes patella and Trichodina mitra, it is shaped like a 

 horse-shoe. In Loxodes bursaria, it is kidney-form, and encloses in one of 

 its extremities a small corpuscle (nucleolus). 



The round nucleus of Euglena viridis has in its c.entre a transparent 

 dot. In Chäodo7i cucullulus, the nucleolus has a similar dot, and thus tha 

 nucleus as a whole resembles a cell. 



§ 



Z6. 



These nuclei, which make Infusoria resemble cells, deserve a special 

 attention, since they do not die with the animal. Thus the nucleus of 

 Euglena viridis, which, according to Ehrenher g,'-^'' is globular when dying, 

 and surrounded by a kind of cyst, remains unchanged a long time, or even 

 increases in size, having no appearance of a dead body. It may be that 

 the life of this animal, under these circumstances, is not finished, but only 

 assumes another form.'-' 



1 Loc. cit. p. 110. Ttiat the nucleus contained in Infusoria plays an 



2 Perhaps this nucleus, of which the animal is important part in the propagation of those animal- 

 only a temporary envelope, is ultimately develuijed «ules, is supported also l)y a recent observation of 

 into a particular animal. Indeed, perhaps this Focke, who witnes.sed the development of several 

 species, as well as many others, are only the kirVäl' 'yodng individuals in the nucleus of Loxodes bur- 

 states of other animals, whose metamorphoses are saria. See Amll. Bericht über die 22 tr. Versaaml. 

 yet unknown. It may jiroperly be asked, if this deutsch. Naturforscher, in Bremen, Abth. ii. p. 

 nucleus has not, relative to the body containing it, 110. 



the same significatiou as have the tubulous larvie 

 of Monostomuin mutabile (see below) to the em- 

 bryos tUey surround. 



