450 M. Eckhard on the Organization 



the rest of the body. They are best seen by allowing the Infu- 

 sorium to decay from the deficiency of water without removing 

 it from the glass-slide. In the work above quoted, Ehrenberg 

 distinguished the following forms, among which all the varieties 

 may be comprised : — 



1. The globular ; 2. the ovate ; 3. the discoid ; 4. the reniform ; 

 5. the ligulate ; 6. the moniliform ; 7. the cylindrical ; and 8. the 

 annular. They appear to be more general than the vesicles, but 

 have not been found in some, although few families. These are 

 the Colepina, Vibrionea, Dinobryina and Arcellina. In regard to 

 these organs also I find in Siebold (§ 21 — 23) some remarks to 

 which I cannot assent. 



a. The nucleus appears to him to be loose in the parenchyma, 

 as the observation can be frequently made that the Infusoria re- 

 volved around the nucleus which remained at rest in their inte- 

 rior. This appearance however cannot so often be perceived, and 

 only when we attentively observe the glands for a considerable 

 time ; it never appears when we first commence observation and 

 observe both the glands and the body. I therefore consider this 

 phenomenon as an optical illusion, especially when I recollect that 

 it would be inexplicable how the glands in the different genera 

 and species preserve so constant a position, which could not be ex- 

 pected in so yielding a parenchyma of the body as Siebold has pre- 

 supposed in his consideration of the relations of nutrition to exist. 



b. At p. 25, in note 2, Siebold supposes that the glands per- 

 haps subsequently became developed into distinct animals, be- 

 cause after the death of the Infusoria they were not immediately 

 destroyed. This also appears improbable to me, because I fre- 

 quently saw these nuclei disappear even in half an hour or an 

 hour, although water was present in sufficient quantity. That 

 they are preserved longer than the rest of the body ought not to 

 occasion surprise, as they are of a more solid consistence. 



Remark. — As regards the occurrence of glands and vesicles in 

 one and the same individual, it must be remarked that in all 

 eases where a vesicle is present the gland has also been shown to 

 occur, or certainly may be demonstrated to occur, as several ob- 

 servations have shown us (Prorodon teres), but that there are 

 some families in which the glands, but not the contractile vesi- 

 cles, have been seen (Bacillarina, Closterina). If both organs are 

 present at the same time, and we coincide in Ehrenberg's view 

 on the use of these organs, the supposition becomes probable that 

 they are connected with one another. This however has by no 

 means been confirmed. 



C. Import of these two organs. 



Ehrenberg corisiders the glands as testicles and the vesicles as 

 seminal vesicles. In truth, this view has not been expressed by 



