NOTES ON NATURAL HISTORY BOOKS. 285 



at the same time, the slit at the entrance, so that when the grub is 

 hatched, it finds a passage ready for its exit. The mother fly seems 

 to be aware of this growth of her eggs, for she takes care to deposit 

 them at such distances as may prevent their disturbing one another 

 by their development/ " The circumstance of the eggs growing as 

 here stated is singular, yet not peculiar to this family, for the eggs 

 of some other insects increase in size after being laid ; but it affords, 

 I may remark, a slight connection between insects and plants, as of 

 some of the latter the seeds, which are equivalent to the eggs of 

 oviparous animals, visibly expand previous to germination. Such is 

 a sketch of the general habits of the Tenthredinidae ; but it must 

 not be accepted as applicable, in all its particulars, to the species 

 under notice, whose history I am sorry I cannot minutely detail, 

 though I do not suspect that, if it were fully described, it would 

 present us with ought remarkably different from this. Should the 

 eggs of the Trichiosoma lucorum be discovered to increase in size, as 

 do those of the majority of Tenthredinidae (and which I have no 

 reason to doubt they do), then the insect becomes doubly inter- 

 esting, by its furnishing us with a similar fact lo that observed in 

 the seeds of plants, and consequently forming a minor point of union 

 between the animal and vegetable creation ; while, in the circum- 

 stance of its antennae resembling those of the Papilionidae, or but- 

 terfly family, a connection is formed between the orders Hymenop- 

 tera and Lepidoptera. The flight of Trichiosoma lucorum probably 

 resembles that of most of its congeneric species in being low and 

 short ; a circumstance that invalidates the opinion of those who 

 assert, merely because they see Saw Flies suddenly appear in great 

 abundance, that they come from the sea. I have but once seen 

 this insect alive in its perfect state, and then it seemed to be of a 

 very sluggish nature : I have seen the larvae three or four times. My 

 friend, Mr. R. Ogilvie, and myself, when in company on a Natu- 

 ral History ramble, had once the pleasure of witnessing a very re- 

 markable circumstance in the larva of this insect, which, upon being 

 touched, spirted out of the pores of its body a thin, watery fluid, in 

 fountain-like jets, of some height, comparing them to the size of the 

 animal. This fact I have recorded in the Magazine of Natural 

 History (vol. vi., p. 157) \ but, in consequence of having been mis- 

 led by a figure in Shaw's Zoology, I have attributed the fact unin- 

 tentionally to the larva of Tenthredo Amerinae, a much rarer spe- 

 cies. In the above journal I have expressed my opinion that the 

 object of its ejecting a liquid upon being disturbed, might have been 

 to repel our liberties, or to induce us to abandon our capture, as the 



