RADIATE APPEARANCES IN OVA • 251 



to the appearance of rays round the contractile vacuole of 

 Amceba terricola. More recently I was able with v. 

 Erlanger (1890) to observe the same thing round the 

 contractile vacuole of Actinoholus. In the same way I 

 found it also in Nyctothertos} I need scarcely remark that 

 this striation is not to be confused with the radiately 

 arranged affluent canals of the contractile vacuole. I 

 only point this out here because Frommann (1890, p. 11) 

 seems to have fallen into this very error when he says 

 with regard to this phenomenon : " In many Infusoria and 

 ia Amceba terricola there radiate out from the circumference 

 of the contractile spaces a number of lacunce (!) into the 

 surrounding parenchyma (!) of the body, into which the 

 parenchymal fluid (!), laden with products of metabolism, is 

 forced by the pressure (!) of the water taken up into the 

 body, and is thus guided to the vacuole." As is proved by 

 the continuation of this passage, Frommann has simply 

 confused the radiating protoplasm round the vacuole with 

 the so-called radial canals, which occur moreover in other 

 species, so that one is quite justified in saying of the passage 

 quoted that it contains as many errors as there are clauses. 



(i) Radiate Appearances in Ova, etc. 



It is notorious that radiating appearances are a very 

 common phenomenon in the protoplasm of egg cells. I will 

 only recall here the observations of Leydig (1872) and 

 Eimer on Eeptilian eggs, of van Beneden (1876), Flemming 

 (1881, 1882) and Frommann on Echinoderm eggs, of 

 Eauber (1883) on the eggs of Triton, the trout, and the 



^ It is interesting that Frenzel in like manner has recently, in a so-called 

 Amosia cubica, observed a very well developed radiate striation round the 

 contractile vacuole. This discovery appears the more important, since it 

 forms, after nearly twenty years, the first confirmation of my observation 

 which was achieved, as it would seem, quite independently, i.e. without 

 knowledge of my earlier observations. It is to be hoped that rather more 

 attention will now be given to this important phenomenon than has been 

 done during the relatively long time it has been known. (See J. Frenzel, 

 " Dntersuchungen liber die mikroskopisohe Fauna Argentinians," Arch. f. 

 inikr. AnaL, Bd. xxxix. 1891, p. 9, Plate I.) 



