226 



HARDWICKE'S SCIENCE-GOSSIP. 



[Oct. 1, 1S70. 



passed through them, and remained unmoved until 

 their particular hour for flight arrived. There is no 

 question but that in these cases, the insects feel the 

 presence of the pin, yet the sensation is not so 

 acute as to cause uneasiness ; and it is only the 

 evening which rouses the creature's activity, and 

 its desire to escape. A beetle, again, which had 

 been immersed in hot water, and subsequently 

 pinned out, revived, and, the pin being taken out, 

 got all right again, lived for some time, and devoured 

 dead flies, &c, with gusto. 



Here let me add a fact which I have repeatedly 

 observed. There are many caterpillars which may 

 be rougldy handled, and even squeezed, yet they 

 will devour their food as usual, provided no vital 

 injury be given. And those of some species, as for 

 instance, that of the Poplar Hawk (S. populi), will 

 grasp the leaf or twig on which they are resting 

 with [such tenacity, and they cannot be forcibly 

 removed without tearing the body from the legs ; 

 while, were such attempts to remove them painful, 

 it seems natural to suppose that the insect would 

 loose its hold, and allow itself to be withdrawn. 



Multitudinous, too, are the perils which beset 

 insect life. Were they endued with acute sensa- 

 tions, every field, as the plough passes along it, 

 would exhibit its host of miserable and disabled 

 wretches ; nor could we walk along a woodland or 

 garden path, without leaving behind us sad me- 

 mentoes of our tread. The amateur might pause 

 ere he slew hundreds of aphides on his favourite 

 roses, for who can tell the aggregate of suffering he 

 would be inflicting ? Both philosophy and common 

 sense unite in telling us that the nature of an in- 

 sect's life, and its liability to a" sudden' close, de- 

 cidedly show that the sensibilities attendant upon 

 it are few. So, also, may it be said of other classes 

 of animals approximating the Insecta in their 

 structure and mode of existence ; and though every 

 true naturalist will avoid all needless destruction of 

 life, none such need feel that in the operation of 

 " killing," sometimes unavoidable, they are guilty 

 of anything approximating to " murder." 



J. P. S. Clifford. 



VARIATIONS IN SEED-LEAVES. 



TWO very curious instances of variation in seed- 

 lings have just been communicated to me by 

 Mr. Aitken, of Bacup, which differ somewhat from 

 any that were mentioned, either by Mr. Kitchener 

 or myself; or rather, perhaps, that, whereas Mr. 

 Kitchener and I only hazarded a conjecture as to 

 the causes of a multiplicity of cotyledons, Mr. 

 Aitken, having watched the growth of his examples 

 for some time, has made a very interesting and 

 valuable series of observations upon them ; and the 

 facts he has noticed enable us, without any doubt, 



I think, to trace out the cause of their variation. 

 They are both sycamores, which tree seems to yield 

 a greater number of monstrous seedlings than any 

 other plant I have seen. 



Mr. Aitken writes to me : " Some seven or eight 

 years ago I noticed a seedling sycamore with three 

 seed-leaves. This I kept under my eye, in order to 

 observe the development of the leaves, which, to 

 my surprise, grew in threes in a whorl. The leading 

 shoot continues to do this up to the present time, and 

 in no case have fewer leaves than three ever been 

 produced. But this singularity only applies to the 

 leading shoot; for the side shoots or branches, 

 which of course are in threes, only produce two 

 leaves at each joint, as in the ordinary way. I have 

 noticed many seedlings of the sycamore with three 

 seed-leaves, but this is the only one that has con- 

 tinued to carry leaves in triplets." 



Mr. F. V. Paxton, in Science-Gossip (p. 139), 

 mentions a seedling of sycamore with three equi- 

 distant cotyledons, and a plumule consisting of 

 three leaves in a whorl. This, when it grew up, 

 might prove to be exactly similar to the one now 

 described, and it probably had a similar origin; 

 but, as two of the leaves were partially united, it is 

 possible the peculiarity may have arisen from the 

 union of two imperfect embryos ; at any rate, the 

 division of the original cellular mass into three lobes 

 at the earliest stage of its growth, would not seem 

 to have been quite so complete as in Mr. Aitken's 

 sycamore. As this plant has preserved the same 

 triple method of growth for so many years, there 

 would appear to be, in this case, some inherent 

 threefold energy ; and the inference is, that, in such 

 a case, the three cotyledons were formed from the 

 beginning, and were not the result of either chorisis 

 or synophty. There do not seem to have been 

 many cases recorded of the continuance of a triple 

 growth, so it is reasonable to suppose that the 

 formation of a " trifoliar phyton " is the least 

 common way in which to account for the presence 

 of three seed-leaves in an embryo. 



It is not uncommon to find three leaves, instead 

 of two, growing from one joint in Fuchsia, as also 

 Anagallis, and in several other plants. I rather 

 think that this peculiarity, also, is often confined to 

 the central shoots ; but I am not sure, and cannot 

 now find one to examine. Whether this unusual 

 growth arises from the same cause as in the syca- 

 more that has been described, or whether they are 

 cases of chorisis, or of exuberance of growth, we 

 cannot always tell ; but these, and such examples as 

 the sycamore, lead us to strange speculations as to 

 what may be the nature of that force which, in 

 one case, causes a cellular mass to form only one 

 cotyledon, and to have much of its after-growth 

 arranged in threes, to be an Endogen; and, in 

 another case to exert such an influence on a 

 cellular mass that it divides into two cotyledons, 



