C50 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Endosperm of Dicotyledons.* — Prof. C. F. Hegelmaior confirms 

 tho accepted view that tbo nuclei of the endosperm result in almost 

 all cases from division of the secondary nucleus of the embryo-sac 

 which has been formed by tho coalescence of the two polar nuclei. 

 Exceptions appear to occur uniformly in Hibiscus Trionum, and 

 probably in many cases in Adonis autumnalis, where this coalesconco 

 does not take place, but the endosperm is formed by repeated bipar- 

 tition of tho two free nuclei of the embryo-sac which remain distinct. 

 The further development of tho endosperm may vary according to 

 four types, viz. : — 



1. The omnilateral peripheral type. Tho nuclei formed by 

 division from the secondary nucleus of the embryo-sac occupy the 

 whole periphery of the embryo-sac ; tho first cells arise as a simple 

 connected layer clothing the entire embryo-sac, and ultimately filling 

 it up by centripetal divisions. This is the most common mode ; 

 examples are furnished by Adonis, Caltha, Cotoneaster, Malva, 

 Hibiscus, &c. 



2. The peripheral simultaneous type. The cells are formed 

 simultaneously in the entire periphery of the embryo-sac ; there is no 

 later centripetal division of them ; the comparatively narrow embryo- 

 sac being filled up by the first formation: — Bocconia, Scabiosa, 

 Euphorbia. 



3. The unilateral peripheral type. Cell-formation takes place 

 chiefly in the end of the embryo-sac nearest the micropyle ; the 

 tissue formed here afterwards extending towards the chalaza : — 

 Trigonella, Phaseolus, Fagopyrum. 



4. The endogenous type. The first cells of the endosperm are 

 not formed in the periphery of the embryo-sac, but simultaneously 

 throughout the whole protoplasm. In this type alone is the entire 

 mass of the embryo-sac filled uniformly with nuclei before the forma- 

 tion of the endosperm-cells : — Observed only in Eranthis hiemalis. 



The author observed in many cases both direct and indirect cell- 

 division even in cases of normal development. 



Action of Saline Solutions on Germination.! — According to 

 experiments carried out by Herr Jarius, which are described in detail, 

 no injurious effects on the germination of seeds can possibly result 

 from the use of manures, as their solution in the soil can never exceed 

 • 4 per cent. Still the seed should not be sown immediately on the 

 manure, as in such a case it is possible that a stronger solution may 

 be formed. In a table is given the ratio between the growth of the 

 radicle and plumule of several seeds when subject during growth to 

 different strengths of the same solution. 



Action of Hydrocyanic Acid on Seeds.J — Herr E. Schar cor- 

 roborates Schonbein's experiments on the action of hydrocyanic acid 



* Nova Acta K. Leop.-Carol. Deutsch. Akad. Naturforscher, xlix., 104 pp. 

 See Bot. Centralbl., xxv. (1886) p. 302. 



t Landw. Vcrsuchs-Stat., 1885, pp. 149-78. See Journ. Chem. Soc. Lond., 

 Abstr., 1. (1886) p. 90. 



X Journ. Chem. Soc. Loud.— Abstr., 1. (1886) p. 575, from Chem. Ceutr., exxxi. 

 (1885) p. 826. 



