tHE RESTING HABIT OF INSECTS, ETC. 53 



discuss the position apparently (in the detached quotation given) 

 assumed by the late Prof. Romanes, in which he ranks plants and 

 animals in the same category as "machines so constructed that 

 stimuli from the outer world cause them to act in the most purposeful 

 manner for their own maintenance." Yet the arguments urged later 

 on in the article as to the resting habits of insects, rest largely upon 

 the acquired habits and inherited instincts which we all agree to play 

 an important part in animal evolution, and which are evidences of the 

 self-assertion of the organism which often, it is true, but not 

 invariably, " act in the most purposeful manner for their mainten- 

 ance." Again, in the quotation from Prof. Weismann, the habit of 

 hybernation of the marmot is discussed as though the molecular or 

 histological changes effected in the tissues by cold or other influences 

 were alone to be taken into account. Now, although we must acknow- 

 ledge that all the phenomena of life are ultimately referable to the 

 potentialities of protoplasm, it only obscures the issues if, when dis- 

 cussing the actions of highly organised creatures, we ignore those 

 qualities which, at any rate in degree, distinguish the higher animals 

 from the plants. The agency of sensations in giving rise to simple 

 ideas no doubt is primary, but the complex secondary influences of 

 memory and acquired morphological adaptations upon the action of 

 the organism have also to be reckoned with. And it is evident, from 

 the whole tenor of the succeeding article, that its author fully acknow- 

 ledges this. Three sets of factors, therefore, appear to me to control 

 the results. Firstly, The hammering of the environment upon the 

 organism. Secondly, The directly resulting reaction. Thirdly, The 

 interference of Inherited Habits, Morphological Adaptations, and 

 Acquired Instincts (which may be termed ancestral memories) ; all of 

 which no doubt are derived originally in the race from the respective 

 interaction of the first two factors, but which now act automatically 

 and independently of them. It is this third set of factors which 

 renders the results of external influences variable and often inexplic- 

 able, being blind traditional survivals of adaptations which may now 

 have become unnecessary or even partially or wholly unsuitable. The 

 peacock in this climate adheres to the periodicity of its moult, shed- 

 ding its feathers at the advent of winter, and shivering of nights on 

 the housetop in the " wild west wind " till a neAV coat has grown. To 

 a bird of less hardy constitution, this combination of two surviving 

 habits would soon prove fatal. The lemming's strange migratory 

 instinct also, which leads to its annual decimation, is well known. 



In proceeding to discuss the origin of the hybernating habits of the 

 Lepidoptera, Mr. Tutt points out that the direct action of cold or heat 

 does not seem to account sufficiently for the varied catena of ancillary 

 phenomena, and goes on to question " whether cold is the external 

 stimulus which . . . causes the reaction of hybernation." "Have 

 we ever yet proved a causal connexion between cold and hybernation ? 

 I do not think so." And after suggesting that the failure of the food 

 supply is a cause which may act in some cases, and probably was the 

 chief agent in inducing the hybernating habit in most, he gives 

 reasons for thinking that this would not completely solve the diffi- 

 culty, since there are some both imagines and larva^ which hybernate 

 long before their pabulum grows scarce. He then propounds the 

 rather abstruse but ingenious theory that the encysting of protozoa 

 and some microscopical metazoa (which is in some instances a method 



