Natural History of the Vorticellge. 203 



Spirostormim^ &c.), and seems only to have transferred them 

 from these to the Vorticellaj. 



With regard to this, he says*: — " The stride (of Spirosfonmm 

 ambigimm) consist of a homogeneous soft mass, rendered 

 cloudy by very densely packed, extremely fine granules, and 

 are connected with each other by means of a hyaline, firmer, 

 but much narrower intermediate substance, which is evidently 

 a part of the cuticula. Of course the sti'iae are also clothed 

 externally by the cuticula ; but it is not here separately per- 

 ceptible, because it clings most intimately to the cloudy sub- 

 stance of the strise." Further on, recommending the blue forms 

 of Stentor cceruleus as particularly favourable for the investi- 

 gation of the body-strife, he says of it : — " The stria? here, 

 in the broadest part of the body in large and not perfectly ex- 

 tended individuals, form broad ribbon-like cords, more or less 

 strongly convex externally, which make their appearance with 

 particular distinctness in the blue Stentors, because they are 

 of an intense blue or verdigris colour, whilst the narrower 

 clear interspaces remain almost colourless. In their composi- 

 tion the strife consist of a homogeneous, clear fundamental 

 substance, which cannot be distinguished from the rest of the 

 sarcode of the body ; but in this there are imbedded, close to- 

 gether, innumerable very fine granules, which strongly refract 

 light and in the blue Stentors have a blue colour. The more the 

 animals shorten themselves or widen in one spot, the broader 

 do the stria? become ; on the contrary, if the body-part extends 

 much in length, the strise become converted into the finest 

 lines : the substance of the striae must therefore be a pasty 

 mass which flows up and down, or, if it be prefeiTcd, a viscid 

 fluid. Even in moderately contracted Stentors, and still more 

 in those which have contracted themselves into a spherical or 

 pyriform shape, the strige may be seen throughout their whole 

 length furnished with dark transverse lines lying close behind 

 one another, by which the strife acquire a striking resemblance 

 to transversely striated muscular fibres, &c." 



In what follows Stein then endeavours to demonstrate the 

 accordance of the muscular strife of the Infusoria thus consti- 

 tuted with the muscular fibres of the higher animals, especially 

 by identifying the fine granules imbedded in the body-stria? 

 with the disdiaclasts of the transversely striated muscles, as 

 they, even by their " very regular accumulation in groups, 

 produce a remarkably distinct transverse striation." Finally, 

 in order to establish the relationship completely, it is main- 

 tained, as already remarked, that the cuticula enveloping the 



* Der Organismus der Infusionsth. Abth. ii. p. 28. 



