|0 Stop es and Fujii, Tne autritive relations of the suixonnding tissues etc. 



The migration of the food also follows mudi the same course 

 ae in the Cycads. We had however a naore complete series of 

 materials of different Stades of development alter the formation of 

 the starch grains in the endosperm, than we had for the Cycads, 

 and will now summarise the results of observations on material 

 collected at intervals of every 2 — 3 days. Willi Ginkgo there is 

 great aniformity in t he development of the different ovules on the 

 same fcree or eveo on different trees growing in the sann 1 place, so 

 that more value attaches to dated observations for Ginkgo than Cor 

 the Cycads where there is much irregularity even in one and the 

 same cone. 1 ) 



For this pnrpose we nsed prineipally microtome series, passed 

 into water or alcohol as the case demanded, and exainined in 

 lodine. In the course of one nionth (Aug. 28 th to Sept. 30 th ) the 

 changes were as follows. Begiuning with a stage in which the 

 endosperm cells in general contain-ed many starch grains, we found 

 the grains smaller in the cells nearer the archegonia and a little 

 larger in the cells of the jacket layer, while the egg cell was free 

 from starch. In the next stage the grains in the jacket cells were 

 smaller and stained a brownish rather than the true blue violet of 

 the storage starch of the rest of the endosperm; very small 

 brownish violet grains also began to appear in the egg cell. This 

 difference in the nature of the starch in the slieath cells was also 

 observed in permanent preparations of microtome series which had 

 been stained with Flemming's triple stain from which the Gentian 

 violet was almost entirely washed out. In these the large storage 

 starch grains of the nsual endosperm cells were stained pale fiesh 

 colour, while the grains in the jacket cells were blue. Tbese 

 reactions certainly show that the starch grains in the two regions 

 were in somewhat different conditions, probably indicating that the 

 starch in the jacket cells was just being transformed into soluble 

 carbohydrate by diastase secreted in the jacket cells. In later 

 stages the starch steadily decreased in the jacket cells. in which 

 the grains were sometimes grouped together to one side of the 

 cells in a curious mauner (like the arrangement in the "statolith" 

 starch grains) for which we have as yet no explanation. In these 

 stages the number of starch grains in the egg increased. The 

 jacket cells then emptied themselves of starch, beginning at the 

 base of the Arcbegonium tili they were finally completely emptied 

 in about 3 weeks from the first mentioned date. The emptying of 

 the cells of starch spread in an outward direction in the endosperm 

 tili the zone immediately round the archegonia for 10 — 15 cell 

 layers was free from it, just as was the case in the Cycads 

 (cf. figs 7 and 8). We jndged in both cases from the various facts 

 observed, that this starch, temporarily stored in the endosperm, 

 was being transformed into soluble carbohydrate and passed into 

 the egg cell. 



x ) Dr. Miyake inforuied us of great irregularity in the development of 

 the ovules of Zamia floridana. 



