436 SUMMARY OF CURRENT RESEARCHES RELATING TO 



(2) Nutrition and Growth (including Germination, 

 and Movements of Fluids). 



Chlorophyll-Assimilation through the Bark.* — Mdlle. M. Goldflus 

 has carried out a series of experiments — for which a special apparatus 

 was made — on a great variety of woody plants, tending to show that 

 these do not depend so largely as has hitherto been supposed on their 

 leaves for their chlorophyll-assimilation. Chlorophyll always occurs, 

 in larger or smaller quantities, in the branches. It is always formed in 

 the trunk, but is limited to the bottom of the crevices when the outer 

 bark splits. The authoress concludes that chlorophyll may be formed in 

 every living tissue without distinction of position ; and that its forma- 

 tion and localisation depend entirely on physiological conditions. Trees 

 assimilate through their whole surface, in winter as in summer ; hence 

 the phrase " winter-rest " is only a comparative one. 



Chlorophyll-Assimilation outside the Living Plant.f — By mixing 

 together an extract of the soluble constituents of leaves in glycerated 

 water and a green powder obtained from leaves at a temperature above 

 100° 0., J. Friedel has succeeded in obtaining the chlorophyll reaction 

 on exposure to light, independently of the living plant. It is appar- 

 ently due to the action of a diastase present in the powder. 



Cytisus Adami. — W. Beijerinck J stimulated into development the 

 dormant buds in the branches of this graft-hybrid between Oytisus 

 Laburnum and C. purpureus, by severe cutting-back. The branches from 

 these buds exhibited generally a more or less complete reversion to one 

 or the other parent-type ; in a few cases they exhibited the characters of 

 one parent in one (longitudinal) half, of the other parent in the other 

 half. 



Dr. B. Laubert § obtained somewhat similar results ; the reversions 

 to the C. purpureas type reproduced the characters of the i)arent-form 

 in every particular. In no case did any branch exhibit transitional 

 characters between those of one and those of the other parent-form. 



Growth in Length of Petals and Fruits.|| — A. Kraetzer records 

 the observation of a " great period " in the growth in length of petals 

 and fruits similar to that established by Sachs in the case of stems and 

 roots. In the case of flowers the great period is either immediately 

 before or immediately after the opening of the flower and the shedding 

 of the pollen. In Mirdbilis longifiora the rate of growth of the petals 

 increases during the four days before opening from 3 to 34 mm. per 

 diem, completely ceasing on the following day. In fruits (Cucurbitacea?) 

 the zone of most active growth is usually towards the base of the fruit. 



Grafting the Potato on the Potato.^ — Further experiments by 

 E. Laurent confirm his previous conclusion that, in grafting one variety 



* Kev. Ge'n. de Bot. (Bonnier), xi. (1901) pp. 49-62 (2 pis. and 2 figs.). 



t Comptes Rendus, cxxxii. (1901) pp. 1138-40. 



\ S.B. k. Akad. Wetensch. Amsterdam, 1900, pp. 365-71. See Bot. Centralbl 

 Ixxxv. (1901) p. 333; also Bot. Ztg., lix. (1901) 2'" Abt., pp. 113-8 (2 fiVs ) 



§ Beih. z. Bot. Centralbl., x. (1901) pp. 144- (35 (9 figs.). 



|| ' Ueb. d. Langenwachsthum d. Blumenblatter u. Friichte,' Wurzburg, 1900, 

 50 pp. and 1 pi. See Bot. Centralbl. lxxxvi. (1901) p. 20. 



«|[ Bull. Soc. r. Bot. Belgique, 1900, pp. 85-90. Cf. this Journal, 1900, p. 607. 



