o4 Olive. Mitotic divisidii nf tlic ihr- Um of 1Ii(> ( "\'an(i|iln-ceae. 



is ;i<jjaiii calk'd. liowever, to tlie historical table oii [>. 'J, wliich 

 })ivsent.s a inost iiiterestino- variety of conchisions concernin<r 

 theso inclnsions. But I wish to record here some difforences of 

 opinioii as to tlio position in tho cell of tlio "Tanulos. Bütschli 

 (})0) aiid otliers ihouglit tliat tlio slimo globiües weru chroiiiatiii 

 granules and naturally believed that they occured within the 

 central body; altliough, in sonie liigher plants, Bütschli found 

 them scattered througli the whole protoplasm. Kohl (03j, pro- 

 bably because he had not examined the matter in sections, 

 agrees that they occur only in the nucleus. Hegler says, on 

 the otlier hand, that the „slime vacnoles", as he calls them, as 

 well as the cyanophycin grannies, lie only in the cytoplasm, 

 outside the nucleus. Fig. 27 is a cross section of O.sciUatoria, 

 showing a largo slime globale, obvionsly imbedded in one side 

 of the nucleus. Fig. 8 represents a preparation, likewise stained 

 with iron haematoxvlin, in which the slime globules are stained 

 more or less dark. In this figure, one such body is shown, 

 pressed into one side of each nucleus. On the other hand, 

 certain minute globules in figs. 7, 11 and 13 seem to be actually 

 enclosed within the limits of the central body. Therefore, whilc 

 it appears possible, since there is no nuclear membrane, that the 

 slime globules may be sometimes, entirely enclosed by the sub- 

 stance of the central body, they lie usually in the cytoplasm in 

 the immediato vicinity of the nucleus. 



The cyanophycin granules may sometimes be seen witli high 

 powers in living plants of 0.sciUatona and other forms (fig. 1). 

 Their relative position is much better shown, however, in sections 

 which have been stained witli eosin , e. g. , together witli some 

 other differentiating stain to bring out the nucleus and other 

 parts of tlie ceU. Fig. 21 is such a preparation of an unde- 

 termined species of Oscillaforia and hg. 22, of the minute sjjecies, 

 0. splendcns. In both cases, the cyanophycin granules lie in 

 the cj'toplasm, in close proximity to the cross walls. In one 

 cell in fig. 21 is shown a minute refractive crystal, lying in a 

 vacuole, where, normally, the cyanophycin occurs. In fig. 23, 

 the granules are shown in a cross section of Oscillaforia. Fig. 48 

 represents a preparation of Caloflirix in which the granules are 

 stained with safranin, and fig. 56, of Nostoc, similarly pre- 

 pared. In these last drawings, as well as in one of Cijlindro- 

 spenniim (fig. 77), we observe that the granules occur, scattered 

 irregularly, throughout the cytoplasm. 



Experiments with digestiou. 



Some experiments were undertaken by the writer in order 

 primarily to discover whether the assertions of Fischer (97) 

 are correct in regard to certain conclusions of Zacharias (87) 

 and Bütschli (90). Zacharias claimed that pepsin partl}^ 

 digested the peripheral cj'^toplasm in OsciUatoria^ leaving the 

 undigested chromatin of tlic central part as granulär, refractive 



