On the Belgian Equivalents of the Easteim- Counties Drift. 393 



injected beneath the epidermis of two caterpillars, and into a 

 third the same quantity of distilled water. They were all swelled 

 out, and suffered apparently from the distention, but equally, 

 and in forty- eight hours were all equally recovered. 



{Exp. 6.) Several caterpillars were subjected in various ways 

 to the action of hydrocyanic acid, and all quickly died. From 

 this it was proved that this caterpillar possesses no mithridate, 

 no universal panacea against all poisons. 



It may be fairly inferred, from the preceding experiments, 

 that 



(1.) The caterpillar of Deiopeia pulchella feeds on the virulent 

 poison contained in the kernel of the seed of Physostigma ve- 

 nenosum; and that 



(2.) This caterpillar is unaffected by the poisonous principle 

 of the kernel — eserinia. 



The bearing of the second result on our ideas of vital action 

 should not be overlooked. A somewhat analogous case is fur- 

 nished by the Anthonomus druparum, which feeds on the kernel 

 of Prunus cerasus*; and the poisonous properties of this kernel 

 are well known to depend on the hydrocyanic acid it contains f. 

 Here, then, our difficulties are increased : Deiopeia pulchella is 

 unaffected by one poison, but is rapidly killed by hydrocyanic 

 acid ; and this latter occurs in the food of another insect, Antho^ 

 nomits druparum. If life be " the sum total of the functions 

 which resist death," we have in these examples two organisms, 

 each furnished with an exceptional potency of one or more of 

 these death-repelling functions, or having bestowed on each, for 

 a necessary purpose, a special, almost unrecognized, and cer- 

 tainly uninvestigated alexipharmic. Unfortunately, we have no 

 knowledge of those intimate and primary structural changes 

 which accompany every vital action, and our acquaintance with 

 the perversions of such changes is quite as unsatisfactory. 

 Edinburgh University, April 1864. 



XXXVIII. — On the Belgian Equivalents of the Upper and Lower 



Drift of the Eastern Counties. By S. V. Wood, Jun. 

 In describing the lower-Drift sands and gravels that occupy 

 the counties of Norfolk and Suffolk, and of Essex north of 

 Chelmsford, and which, at varying distances from the coast, 

 pass under the Boulder-clay or upper Drift, and reappear at the 

 surface from the denudation of the latter on the western side of 



* A Manual of Entomology, translated from the German of Dr. Her- 

 mann Burmeister by W. E. Shuckard, M.E.S., 1836, p. 356. 



t A Treatise on Poisons, by Robert Christison, M.D., &c. &c., 1845, 

 p. 787. 



Ann,^ Mag. N. Hist. Ser.3. Vol.\m. 26 



