■558 SUMMARY OF CURRENT RESEARCHES RELATING TO 



cells. This appears to be opposed to the facts in the case of the move- 

 ments of the awns of Pelargonium, Stipa, &c, where the large-celled 

 tissues with thin-walled cells seem to have the greatest power of swel- 

 ling ; but this is owing to a confusion between the apparent swelling 

 of the tissue and the actual swelling of the cell-wall. Torsion, as in 

 the awns of Geraniaceae, the legumes of Papilionaceae, &c, results from 

 the presence of a very hygroscopic tissue on the face which is internal 

 in respect to the torsion. The protection of the pollen and of the fruits 

 in the Cynaraceae is effected by the movements of special organs, the 

 bracts of the involucre. Hygroscopic movements may take place in 

 dead as well as in living tissues. 



Plagiotropic Change of Orthotropous Roots. * — B. Nemec recalls 

 the fact that when not very young roots of seedlings are placed in 

 water or moist air in a reversed position, they become, after a short 

 time, plagiotropic. This he shows to result from the fact that in such 

 orthotropous roots which have become plagiotropic, the accumulations 

 of protoplasm acquire the same distribution as in plagiotropio lateral 

 roots. 



(4) Chemical Changes (including: Respiration 

 and Fermentation). 



Formation of Proteids in Plants. f — W. Zaleski has already pointed 

 out that the increase in the amount of proteids in the germinating bulbs 

 of onions is not due to the process of germination, since it takes place 

 also when the bulb is in a resting condition. Further experiments now 

 show that the cutting up of roots and tubers into small pieces greatly 

 promotes the activity of the production of proteids ; and this appears 

 to be due to the increase in the amount of surface exposed to the action 

 of oxygen. It does not take place in an atmosphere devoid of oxygen. 



Growth of the Bamboo.} — K- Shibata finds that, when vegetation 

 commences (in Japan) the reserve-starch is quickly transformed into 

 cane-sugar, glucose being produced only as a transitory formative ma- 

 terial. In the copious decomposition of albuminoids in the rapidly 

 growing shoots tyrosin is formed in considerable quantities, while 

 asparagin can be detected only locally. Nitrates are formed in the 

 young secondary roots, which are always infested by a fungus. Other 

 inorganic substances detected were potassium, calcium, magnesium, 

 phosphorus, chlorine, and sulphur. 



Normal and Intramolecular Respiration. § — Prof. G. J. Peirce 

 points out that the object of respiration in plants is not the maintenance 

 of a certain body temperature, together with the production of energy 

 needed for doing work, as in warm-blooded animals ; it is merely the 

 production of energy for doing work, as in cold-blooded animals. 



The diastase formed in the germinating seed, dissolving the starch 

 deposited in the seed as a reserve-food-material, and converting it into 

 sugar, makes the reserve-food available for at least three purposes : — 

 (1) for the construction of nitrogenous compounds (amides and pro- 



* Ber. Deutsch. Bot. Ges., xix. (1901) pp. 310-3 (5 figs.), 

 t Tom. cit., pp. 331-9. Cf. this Journal, ante, p. 438. 



\ Journ. Coll. Sci. Imp. Univ. Tokyo, xiii. (1900) 69 pp. and 3 pis. See Bot. 

 Ztg., lix. (1901) Abt. ii. p. 155. 



§ Amer. Nat., xxxv. (1901) pp. 463-75. 



