334 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Physiology. 

 Nutrition and Growth. 



Grafting of Plants containing Hydrocyanic Acid.* — L. G-uignard 

 has made experiments with the object of discovering whether there is 

 any migration of chemical substances from the graft to the stock, or 

 vice versa. The researches hitherto made in this connection dealt with 

 the migration of alkaloids, e.g. atropine, but the author regards them 

 as unsatisfactory, since it is not certain what part is played by alkaloids 

 in plant physiology. On the other hand, the various compounds of 

 hydrocyanic acid are known to have an important function in food- 

 elaboration, and are very easy to detect, and therefore the present 

 experiments deal with plants rich in these substances. The plants used 

 as grafts and stocks were Phaseolus lunatics and the ordinary Haricot 

 bean ; and Photinia and Cotoneaster, with the hawthorn and the wild 

 quince. The results show that when a plant containing a hydrocyanic 

 glucoside is grafted on a plant destitute of this substance, or inversely, 

 there is no migration of the substance. Among the Rosacea? such 

 migration did occur, but only in different species of the same genus, 

 both of which had the power of elaborating the same glucoside. The 

 author concludes that, in spite of the interchange of substances between 

 stock and graft connected with common nutrition and development, 

 certain organic principles remain localised in the one or the other. 

 Grafting represents an artificial symbiosis, in which each species retains 

 its own individuality. 



Seed and Soil Inoculation for Leguminous Crops.f — W. B. 

 Bottomley publishes the results of his experiments with crops inoculated 

 with nitrogen-fixing bacteria. The author distributed more than a 

 thousand specimens of his culture, and about 80 p.c. of the reports 

 received showed an increase in crop. Fifty-two reports are quoted, but 

 only nineteen cases give figures, and there is so great a disparity in the 

 results that no discussion is possible. So far as they go, it appears that 

 a culture has been obtained which, in suitable cases, may increase the 

 yield of leguminous crops 30 to 50 p.c. It is not claimed, however, 

 that the culture cures " sickness " or increases the frequency with which 

 leguminous crops can be grown, and inoculation is found to fail when 

 the soil is too acid, or when it is deficient in lime, potash and phosphates, 

 or when drainage is needed. 



Formation of Aleurone Grains.f — J- Beauverie contributes a note 

 upon the globoids of aleurone grains. The metachromatic properties of 

 the globoids render it easy to follow the different stages in the formation 

 of the aleurone grain. The appearance of the globoids precedes that 

 of the crystalloids and the amorphous substances. The granulations 

 possessing the properties of the globoids appear early in the nucellus and 

 endosperm, and even in the integuments where no globoids are formed. 

 It appears that, contrary to the usual opinion, the globoid-substance has 

 an independent existence within the grain, and can exist apart from the 



* Comptes Rendus, cxlv. (1907) pp. 1376-80. 



t London, ' Country Life ' Office. See also Nature, lxxvii. (1908) pp. 330-31. 



j Comptes Rendus, cxlv. (1907) pp. 1345-47. 



