Stopes and Fujii, The nutritive relations of the surrounding tissues etc. 13 



starch in a median zone, and the pollen tubes which reached almost 

 to the egg were packed with large storage grains. In the endosperm 

 cells at the base of the egg cell a few grains niay have collected, 

 but in the egg cell itself there were none. When the pollen tube 

 had just discharged into the egg cell we found the large storage 

 starch grains from it lying together in the tip of the egg or near 

 the nucleus in the upper part, and in some cases half in and half 

 out of the pollen tube. A little later these big grains lay scattered 

 all through the cytoplasm of the egg, having been carried round 

 by a Streaming of the cytoplasm? These large grains were quite 

 different in appearance from the transitory starch usually found in 

 the egg cell, and they were speedily used up by it. 



Thus there are at least three different series of starch grains 

 to be found in the egg cell, a) The small grains scattered in the 

 cytoplasm itself before the "nutritive vacuoles" are formed and 

 which seem to be subject to daily periodicity. b) The small grains 

 in the "nutritive vacuoles'" the presence of which varies even among 

 ovules of the same cone. c) The large grains brought by the 

 pollen tube and speedily used up by the egg cell. All these grains 

 of starch in the egg cell seem to be used up in the course of its 

 activities. 



After the formation of the embryo a number of the "nutritive 

 vacuoles" still retained their normal appearance; even when the 

 suspensors were so big as to carry the embryo to the very middle 

 of the endosperm, they were to be observed intact, sometimes also 

 with the starch grains in them. At this time there were but few 

 starch grains in the suspensors themselves, and their cell walls (like 

 that of the egg) contained amyloid, for in a fresh condition they 

 stained bluish with iodine. 



With the formation of the embryo, starch began to collect in 

 the cells of the endosperm at the base of the egg cell and in the 

 cells surrounding the embryo, but the endosperm as a whole did 

 not get filled tili very late. 



The origin of the protein grains in Pinus as in the Cycads 

 and Ginkgo is to be looked for in some forms of soluble protein 

 Compounds such as amides or hexonbases, which pass in through 

 the endosperm from cell to cell. Whether or not the nucleoli of 

 the jacket cells play an important part in working up the protein 

 before its entry to the egg cell as suggested by Ferguson is 

 difficult to say just yet. It does not appear to us to be quite 

 reasonable to look for the sole supply of protein nourishment for 

 the egg to the nuclei of the jacket cells; nor is Ferguson's 1 ) 

 view that secondary nucleoli develop in the egg to be the "nutritive 

 spheres" to be easily accepted. Arnoldi's extraordinary results 

 can be explained as suggested by Strasburger 2 ) as due to 



') Ferguson. M. C, „Contrib. to the know. of the life hist. of Pinus". 

 (Proc. Washington Acad. of Sei. Vol. VI. 1904 see p. 107.) 



2 ) Strasburger. E.. „Ueber Plasniaverbindungen pflanzlicher Zellen" 

 (Jahrb. f. wiss. Bot. Vol. 36. 1901. p. 493—606. see p. 550—552.) 



