Stopes and Fujii, The nutritive relations of the surrounding tissues etc. 9 



becomes the deepest crimson. This is particularly noticeable in 

 Dioon and Encephalartos, but holds good for all species examined. 



The formation of starch grains in the egg cell from the 

 plentiful supply of sugar is readily explained by the presence of 

 plastids which we observed there in large numbers, but the formation 

 of solid protein grains in the egg is not so simply explained. We 

 endeavoured to obtain some information as to the natura of these 

 protein grains in different parts of the tissues by the use of 

 artificial pepsin digestion. 1 ) For this we found Macrozamia spiralis, 

 in which the protein grains in the egg are large, and those in the 

 jucket cells similar to them, very good material. We used band 

 sections of alcohol material well washed in water and treated with 

 a mixture of 3 parts • 3 °/ H.C1 in H 2 + 1 part pepsin glycerine, 

 and kept in this digestive fluid at a temperature of about 40 ° C. 

 After treatment for 14 hours the protein granules in the egg, and 

 nearly all those in the jacket cells had lost their high refraction 

 and become "ghostly" remnants of their former selves with little 

 or none of their previous active staining power. The chromatin 

 bodies of the egg nucleus however became much more brilliantly 

 refractive than before (as is characteristic of chromatin after such 

 treatment) while the nucleolus of the egg cell became slightly 

 granulär in appearance. In other cases, after 21 hours the protein 

 granules of the egg cell and most of those in the jacket cells were 

 completely digested, the nucleoli of the egg and jacket cells 

 remaining undigested, with a few other small grains. 



This result proves that the nucleoli and protein grains are 

 different in chemical structure so that one can hardly look to the 

 nucleoli of the jacket layer as their direct source as some authors 

 have done. So also the fact that protein grains just like those of 

 the egg exist in extremely large quantities in the endosperm cells 

 makes it difficult to think that the nucleoli alone should build 

 them up. It seems to us rather that the protein substance 

 accumulates in the endosperm cells, entering in soluble and 

 probably simpler forms, and that in both egg and endosperm cells 

 it is rebuilt in a semiviscous State, when it begins to concentrate, 

 forming granules. The large irregulär form of the grains certainly 

 Supports this suppositiou as does also the appearance of the cell 

 Contents of the endosperm in which the various stages of the 

 granulation are to be seen. 



Ginkgo biloba. 



After what has been said about the Cycads, there is no need 

 to enter so fully into the details of Ginkgo, in which most parti- 

 culars of the structure of the female gametophyte are extremely 

 similar. 



*) Zacharias, E.. ..("ober d. ckem. Beschaffenheit d. Zellkerns-'. (Bot. 

 Zeit. 1881. p. 169 to 176.) ,.Ueber d. ehem. Beschaffenheit v. Cytoplasma u. 

 Zellkern". (Bericht, d. I). Bot. Ges. Bd. XI. 1893. p. 293—307.) ..Ueber 

 Nachweis u. Vorkommen v. Nuclei'n". (Bericht, d. D. Bot. Ges. Bd. XVI. 1898. 

 p. 185—198.) 



