828 M. M. Mercatr 
plasm. Opalina is referred to as agreeing with the other Infusoria 
in never having the glycogen granules in the nuclei. 
BawBIANI (1881) makes brief reference to observations of EnGEL- 
MANN and of ZELLER upon the division of the nucleus in Opalina. 
Kenv (1881—1882) gives good diagnoses of the five species of 
Opalina then known. He quotes ENGELMANN’s and ZELLER’s descrip- 
tions of the phenomena of encystment and the growth of the young 
animals in the tadpoles. Many of ZeLuEr’s and ENGELMANy’s figures 
are well copied. The hosts of O. intestinalis are given as Pelobates 
fuscus and Rana esculenta {in both of which it is very rare, its 
usual hosts being Bombinator pachypus and B. igneus|. 
KRUKENBERG (1882) in a discussion of digestion refers to Opalina 
among the animals which do not ingest solid food. 
Dr Lannesan (1882) gives a very brief description of Opalina and 
says that the Opalinae are doubtless descended from non-parasitic 
forms which became parasitic and gradually lost mouth and anus. 
Brief reference is made to the cysts and to the reproduction. 
Stokes (1884) describes O. flava n. s., from Scaphiopus holbrooku, 
the Hermit spade-foot Toad of eastern North America. 
Nusspaum (1884) a preliminary notice of Nusspaum 1886. 
BaRFURTH (1885) includes O. ranarum in a general discussion 
of glycogen in the bodies of animals. He showed that, when trea- 
ted with “Jodgumm” or with iodine glycerine, some individuals re- 
mained merely yellow, others showed in certain restricted areas of 
the body a red brown color “characteristic of glycogen”. the color 
sometimes being diffuse, sometimes following the lines of the cilia. 
Under higher magnification irregular masses of glycogen were found 
staining brown, while near them were many light yellow strongly 
refractive drops of another substance (“fat”) [probably the refractive 
spherules of the endosarc]. 
Vow KOLLIKER (1885) says (p. 23) that division in multinucleate 
forms like Opalina, which takes place without codperation of the 
nuclei, is not comparable to true division among the protozoa, for 
the fragments do not grow to the size of the parent, but continue 
their division until they become very minute particles comparable 
to spores. The process may be described as cell-formation without 
division of the nucleus. [The distinction is superficial, not funda- 
mental. Nuclear division, of course, occurs, but the properly 
concomitant divisions of the body are for a time suppressed, to 
appear later, in the spring, when the animals are preparing for 
encystment. | 
