ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 737 



chromatic protoplasm which is in contact with the earlier formed nuclei 

 of the endosperm, and gradually disappears as the latter develops. Its 

 place, however, remains empty, and can he found in the ripe seed separat- 

 ing the embryo and endosperm from the persistent nucellus above the 

 chalaza. Thus, after having played the part of an absorptive structure 

 the antipodal mass has a protective role preventing the digestion of the 

 nucellus by the endosperm. 



Chi ff lot, J. — Sur la Structure de la graine de Nymphaea flava Leitn. (The 

 structure of the seed of Nymphxa flava Leitn.) 



Comptes Bendus, cxxxvi. (1903) pp. 1584-6 



Physiology. 

 Nutrition and Growth. 



Alkaloids as a Source of Nitrogen.* — L. Lutz, as a result of ex- 

 periments with various fungi, concludes that alkaloids may serve as 

 plastic material if sufficient nitrates are present ; in the same way that 

 an excess of carbohydrate enables a plant to make use of asparagin. 

 The author points out that plants which are rich in alkaloids when grown 

 in poor soil, become poor in alkaloids when grown in gardens or in a soil 

 which is rich in nitrates. 



Nutrition of Chrysanthemums.t — A. Hebert and G. Truffaut find, 

 from manurial experiments with these plants, that phosphoric acid is 

 of especial importance. The application of manures is only without 

 effect when the soil contains at least 25 per cent, of total nitrogen, 

 • 15 per cent, of phosphoric acid and • 125 per cent, of potash. On com- 

 parison of the produce obtained from unmanured soil with that from 

 fully manured soil, the authors found that, whilst the total yield in the 

 latter case was considerably increased, the percentage amounts of nitrogen 

 and of the ash contituents were not materially altered. 



Germination of Orchids : a Symbiotic Relationship. J — N. Bernard 

 has studied the germination of seeds of Cattleija, Lcelia, and their 

 hybrids. At the end of a fortnight, when sown on damp sawdust, the 

 embryos form minute green spherules, in which condition they remain 

 for some time. In some cases development does not advance further, 

 and the plantlet is sooner or later destroyed ^by mould. In other cases, 

 after a variable time which may reach one or two months, growth is 

 resumed, but proceeds very slowly and irregularly ; often after four or 

 five months the plants do not exceed 5 mm. in length. They are top- 

 shaped ; at the larger end the terminal bud is formed, while at the 

 narrower they are always found to be infested with a filamentous endo- 

 phytic fungus. M. Bernard's experiments show that the presence of 

 this fungus is a necessary condition of the development of the plantlet 

 beyond the green spherule stage. He has not yet succeeded in deter- 

 mining the nature of this hyphomycetous fungus. 



* Bull. Soc. Bot. Fr., 1. (1903) pp. 118-28. 



t Bull. Soc. Chhn., ser. 3, xxix. (1903) pp. 619-23. See also Journ. Chem. Soc. 

 lxxxiv. (1903) ii. p. 608. 



+ Comptes Rendus, cxxxvii. (1903) pp. 483-5. 



