Pflanzenkrankheiten. — ßacteriologie. — Lichenes. 23 



is discussed. The fungus Metarrhisium anisopliae (Metschni) is an 

 enemy ot" the Froghopper, causing the disease known as "Green 

 muscadine", and it may be useful as a means of eradication. A 

 descriptive aecount of the fungus is given, together with suggestions 

 as to its use as a means of insect control. W. E. Brenchley. 



Rorer, J. B., The Witch Broom disease of Cacao in Suri- 

 nam. (Depart. Agric. Trinidad. IX. 64. p. 32—34. 1910.) 



The Witch Broom disease has been attributed to the action of 

 various species of fungi, causing distortion of growth. An excessive 

 growth of lateral shoots oecurs, together with a shortening of the 

 internodes or the affected twig. Development of the Witch Brooms 

 is rapid, but they soon die off and so offer a point of entrance for 

 insect or fungous parasites. The flowers appear in starlike Clusters 

 and the fruits are affected, becoming hard. Experiments show that 

 the disease is caused by the fungus Colletotriclium hixificum. Nume- 

 rous spores are formed, which attack the young soft tissue of the 

 developing buds and young stems. The mycelium developes rapidly, 

 and causes the characteristic hypertrophies. This particular fungus 

 seems to confine its attacks to the Cacao tree alone. 



W. E. Brenchley. 



Golding, J., Notes on the nature of nitrogen fixation in 

 the Root nodules of Leguminous Plants. (Rept. Brit. Ass. 

 Adv. Sei. Sheffield, p. 582—583. 1910.) 



It is now universally aeeepted that leguminous plants fix large 

 quantities of nitrogen from the air in the soil, the process taking 

 place in the nodule. Each plant possesses its own nodule organism, 

 which undergoes a change of form as the process takes places, and 

 which does not easily adapt itself to any other plant. Assimilation 

 of nitrogen by the nodule continues when it is in the soil, but in 

 a much less degree. Certain conditions in the nodule are essential 

 for free fixation, removal of introgenous growth produets, and pre- 

 sence of carbohydrate for nutritive purposes being two of the 

 needful factors. 



Experiments have been carried on to make the quantitave de- 

 terminations of the amounts of nitrogen fixed. A new method indi- 

 cates that the reaction of the eulture medium employed plays an 

 important part in nitrogen fixation. The results of previous work 

 are summarised. W. E. Brenchley. 



Portier. Digestion phagocytaire des chenilles xylopha- 

 ges des Lepidopteres. Exemple d'union sj^mbiotique 

 entre un insecte et un Champignon. (CR. Soc. Biol. Paris. 

 LXX. p. 702-704. 6 mai 1911.) 



La Chenille de Nonagria typhae qui vit dans les tiges de Typha 

 latifolia englobe dans ses leucoc3>4es des cellules fusiformes analo- 

 gues ä des Bacteries; ces microbes secretent une cellulase qui rend 

 la moelle de Typha assimilable pour la chenille. P. Vuillemin. 



Harmand, Abbe. Lichens recueillis dans la Nouvelle-Cale- 

 donie ou en Australie par le R. P. Pionnier, missionnaire, 

 (Bull, seances Soc. Sc. Nancy. 20 pp. 1 pl. sans date. 1911?) 



L'auteur enumere et decrit 32 especes de Pyrenocarpäs corticoles, 



