100 ClENKOWSKl's REMARKS ON DR. STEIN's 



consequently it must be regarded as a protrusion, and that 

 it had no connection whatever with the original slender 

 peduncle of the Podoj)hrya itself. In fact, I noticed cysts in 

 Avliich this original slender peduncle Avas ajipended to the 

 saccular envelope (fig. 8) . I am unable, therefore, to adopt 

 Stein's "vdew that the Podophry(e are enclosed in a mem- 

 brane, of which the slender peduncle is simply a tubular 

 protrusion."'^ This is true only with respect to the short 

 peduncle of the encysted Podophrycs. 



What afterwards becomes of the cysts I have been unable, 

 in spite of observations continued for months, to determine. f 



Comparison of my fig. 5 with that of Stein (1. c, pi. iv, 

 fig. 31), will remove all doubt as to their representing 

 identical forms. These forms, as has been mentioned, are 

 regarded by Stein as transitional stages from the Yorticella- 

 cysts into Podophryce. I have traced their derivation, step 

 by step, in the same specimens, from Podophry<s ; they are, 

 most certainly, not metamorphosed Vorticella-cysts, but 

 the commencement of the encysting of a Podophrya, — 

 PodophryaX are not formed out of them, but, on the contrary, 

 from the latter arise the forms above described, which 

 Stein looks upon as Podoplirycs remaining at an early stage 

 of development. The metamorphosed contents of older Vor- 

 ticella-cysts, regarded by Stein as the first commencement 

 of the formation of a Podophrya, indicate, according to what 

 1 have seen in other infusorial cysts, § and to what Stein 

 himself states, with regard to Vorticella microstoma, the 

 commencement of the breaking up of the entire contents 

 into numerous smaller " swarm"-cells. 



I now proceed to show the relations of the motile embryo. 



In a watch-glass in which I kept a great many specimens 

 of Hydra fusca in water, numerous Acinetae occurred in the 

 mucoid deposit, which could in no respect be distinguished 

 from those represented in Stein's figures 28, 38, 41, pi. iv. 

 They were oval, spherical, or two- to four-lobed bodies ; in 

 the spherical forms the long slender tentacles were usually 

 grouped in two opposite bundles ; in the lobed forms often 



* Stein, 1. c, p. 141. 



■f Tlie I'odoplirya-cjsts have been described by Dr. Weisse under the 

 name of Orciila trochus. ' Bull, de la Classe l)liYS. math.,' t. v, No. 15 ; 

 t. vi, No. 23. 



X Sic in origine. [Vorticella^'] 



\ I have observed the formation of several cells in the cysts mSlylonychia 

 pustnlafa, S. mi/liliis^ and Nassula ctmbigiia. In the latter, these cells con- 

 stitute j)rotrusions, and their entire contents break up into numerous, mo- 

 tile, monadil'orm corpuscles. 



