12 Stop es and Fujii, The nutritive relations of the surrounding tissuea etc. 



Even in the fresh iinstained conditioa most of the detailed structure 

 of these "protein vacuoles" and t hr grains in the cytoplasm are to 

 be elearl} seeu, particularly with the oil immersion, and they show 

 n Dumber of granules in eaoh which read towards reagents as 



protein substance; thus we see that they are b\ n eans the result 



of fixing as was suggested by Blackman 1 ). Digestion experiments 

 however, which yielded such satisf actory results with Macrozamia etc., 

 were technically very difficult with /'/uns, for im asing sections of 

 fresh materiaJ the vacuoles ran together so that the cytoplasm 

 became unitbrmly granulär even when left in pure water only for 

 a shorl tinie. With prolonged treatment with the warm digestive 

 fluid it was soon iinpossible to distinguish the granules of the 

 protein vacuoles owing to the indistinct homogeneous appearance 

 of the whole rnass of cytoplasm, so that we were unable to determine 

 the effects of digestion on the protein granules themselves. A\ r itJi 

 fixed material on the other band the grannies appeared to have 

 been rendered niore resistent, and the chief granules in a protein 

 vacuole were not digested even after a long tinie in the fluid. 

 With acetic methyl green however, we found that the nuclei of the 

 endosperm, jacket cells, and egg cell stained quite strongly, but 

 that the protein granules in the egg cytoplasm and in the "protein 

 vacuoles'' were hardly stained, if at all. This shows that these protein 

 granules differ from nuclei and have no nuclein as their constituent 

 part. 2 ) 



In some cases, and this appeared to be quite erratic, there 

 were grains present in the protein vacuoles which were exceptionally 

 refractive and which proved on staining to be starch grains (see 

 fig. 10). Thus in the "protein vacuoles" we get not only protein 

 substance, but also carbohydrate in the form of starch grains. For 

 the present we propose the term "nutritive vacuoles" to replace 

 "protein vacuoles", but we will have more to say later on this 

 subject. It is interesting to note that in Hofmeister's 3 ) original 

 paper he figures the „Keimbläschen" so accurately as to appear 

 as if he had observed not only the protein bodies but also the 

 starch grains without recognising them. The starch grains we have 

 observed in these vacuoles are always small, sometimes there being 

 only one or two, sometimes several together. Though they are not 

 by any means always present we have not been able to observe as 

 yet any regulär periodicity in their appearance correspönding to that 

 in the earlier stages described. 



In that stage of the ovule in which the Contents of the 

 pollentube are about to be discharged into the egg cell we found 

 the following conditions. The nucellus tip was quite crammed with 



J ) Blackman, V. H., „Cytol. feat. of fertil. in Pinus sylvestris". (Phil. 

 Trans. Roy. Soc. Lond. Ser. B."l898. see p. 417.) 



2 ) Zacharias, E., „Ueb. Nachweis u. Vorkommen v. Nuclein". (Bericht, 

 d. D. Bot. Ges. Bd. XVI. p. 194—197.) 



3 ) Hofmeister, W., „ V T ergleich. Unters, d. Keimung etc. höherer Krypto- 

 gamen . . . u. d. Samenbildung d. Coniferen". Leipzig 1851. cf. plate XXIX. 

 fig. 1, 3 and 4. 



