07 



obtained by dusting with flowers of sulphur, an operation easily carried 

 out, a cooHe being able to dust 3,600 plants ^vith 4*4 lb. of sulphur in 

 1| hours. Hevea was also attacked by root-boring Lamellicorn larvae 

 and by leaf-eating beetles, probably a species of Haltica. This latter 

 infestation may have been accidental. Besides repeatedly occurring 

 on cofiee and tea, Limacodid caterpillars, probably belonging to the 

 genus Miresa, were also found on oil-palms. 



Tower (W. L.). Inheritable Modincation of the Water Relation in 

 Hibernation of Leptinotarsa decemlineata. — Biol. Bull. Marine Biol. 

 Lab. Woods Hole, Mass., Lancaster, Pa., xxxiii, no. 4. October 

 1917, pp. 229-257. 



The results of nine years of experiments on the introduction of 

 Leptinotarsa decemlineata [Colorado potato beetle] into a desert 

 enviromnent prove that an alteration of the water relation occurs in 

 ways that are adaptive in direction and inheritable in character. This 

 is due to development in the organism of the capacity to hold water 

 within the tissues, so that the intense desiccation of the dry seasons 

 does not result in death. 



The materials used have been pure laboratory strains, the experi- 

 ments being conducted under cage conditions to eliminate complica- 

 tions due to predaceous enemies, parasites and epidemics. The beetle 

 has two yearly generations, the adult hibernating in the soil, emerging 

 as soon as the spring temperature is high enough and giving rise to the 

 first summer generation that matures in July. This summer 

 generation produces a second, maturing in August or early September, 

 which after feeding prepares for hibernation during September or 

 early October. Throughout the experiments, the food was the 

 cultivated potato, all watering being by irrigation about the roots of 

 the plants. 



In hibernation, temperature and humidity in the soil are the two 

 chief factors concerned. Consequently, surviving desert types must be 

 adapted to meet, not only the average hostile conditions, but irregular 

 and extreme manifestations of the environment, often of prolonged 

 duration. 



The full capacity for retaining water in the tissues against the 

 influences of a strongly desiccating en\'ironment is developed at about 

 the sixth generation after introduction, but whether this is due to 

 changes in the permeability of the cell-membranes or to changes in the 

 colloidal contents of the cells there is no evidence to show, although 

 the slowness of loss of water in the tissues on a sudden fall in tempera- 

 ture to freezing point, indicates the greater probability of the latter. 



The question still remains as to whether the alteration is a new or 

 added condition, or the revival of an ancestral one, especially in view 

 of the fact that the reversal of the adapted stock to original conditions 

 has not been found to occur at all readily. 



DupoNT (P. E,.). Insect Notes. — Colony of Seychelles, Ann. Rept. on 

 Agric. & Crown Lands for 1916, Victoria, March 1917, p. 13, 

 [Received 10th December 1917.] 



The Coccids reported include : Aspidiotus aldabricus, sp. n., and 

 A. longispinus on bois d'amande, Pidvinaria pseudo-floccifera on 



