November 1, 1898.] 



KNOWLEDGE 



259 



water comes back renewed activity. But besides drought 

 it is pretty well proof against poisons. It can even with- 

 stand a fairly large dose of that most harmful poison to 

 the vegetable world, Corrosive Sublimate. Hence any 

 noxious matter introduced into the soil would harm it 

 little ultimately ; the utmost it could do would be to retard 

 it for a time. 



This, then, is the history of the smell of earth as 

 scientists have declared it unto us, and its recital serves to 

 further point the moral that the most obvious, the most 

 commonplace things of everyday life — things that we have 

 always taken simply for granted without question or 

 interest — may yet have a story hidden beneath them. 

 Like signposts in a foreign land, they may be speaking, 

 though in a language not always comprehended by us, of 

 most fascinating regions, regions we may altogether miss 

 to our great loss, if we neglect ignorantly the directions 

 instead of learning to comprehend them. 



THEHOOKS ON THE MANDIBLEOFTHE HONEY 

 BEE AND THE GIZZARD OF THE ANT. 



By Walter Wesche. 



IN Knowledge for October, 1895, will be found a drawing 

 from my pencil of the hooks on the mandible of the 

 honey bee, which is the only occasion, so far as the 

 writer knows, that this process has been figured. 

 The hooks are nine in number, and in many mandibles 

 carefully examined I have not found this number to 

 vary ; they are absent in the queen and the drone, and 

 in all the wild bees that I have had an opportunity of 

 inspecting. The rib of chitine running across the hollow 

 of the mandible is present, as are also hairs (in some large 



Fl0. 1. — Hooks on the Mandible of the Houev Bee (Apis melifica) 

 X 140. 



humble bees short and bristly), but not in any degree 

 modified to the form of hooks ; neither is there any indica- 

 tion of their presence on the mandibles of the common wasp 

 or hornet. 



What their use is, is at present unknown. Mr. Frederick 

 Enock says that they are undoubtedly highly specialized, 

 and he " can only wonder at their object." Sir John 

 Lubbock did not know of them, and had no idea as to their 



use. Mr. T. W. Cowan, to whom I had the pleasure of 

 showing them, now agrees with me that they are hooks, 

 and highly specialized, and says that they possibly may be 

 used in drawing out was, the mandible undoubtedly being 

 used in cutting it, when forming the comb. I hazarded a 

 suggestion in 1895 that they might be used in clustering, 

 by hooking on to the claws of the bee above, but I under- 

 stand that this theory is not tenable. Perhaps, after all, 

 they may be of the same use to the bee, as is the iron hook 

 to the man who has lost a hand, and be used in drawing 

 objects out of the hive, or in the care and removal of 

 larva; — but whatever their use, it must be one of great 

 importance to the worker bee, as otherwise it is impossible 

 to account for their modification — an importance equalling 

 that which has developed the hooks on the wings. 

 The Gizzard of an Ant. 



This has been many times figured and described. In 

 McCook's most interesting work on the honey ant of 

 California, there is an elaborate drawing of the intestine 

 and gizzard. The drawing 

 here reproduced is from 

 Lasius niijer, the common 

 black ant of our gardens, 

 seen often stroking and 

 "milking" the aphides. The 

 gizzard is very much the 

 same in appearance as that 

 of the honey ant, but the 

 latteris stated to be chitinous, 

 while the gizzard of L. nhjer 

 seems to me to be calcareous, 

 though I have been unable 

 to verify this by chemical 

 test. It is very brittle, will 

 not take methyl blue stain, 



and cannot be recommended as a good microscopic object, 

 as the edges will not define, or at any rate I failed to make 

 them. In texture it reminded me of the " dart," in the 

 sexual organs of the common snail. 



In this case also, the use of the organ is not known ; 

 ants are generally supposed to feed on fluids, and I believe 

 a good deal of discussion has taken place at various times 

 on the subject. 



The organ consists of four separate parts, the lower 

 portion of each being far less soluble in a solution of caustic 

 potash than the upper — and I have often found the upper 

 part quite dissolved away in the preparation of a whole 

 mounted insect. I have not been able to find the gizzard 

 in the common sugar ant (Diplorhopirum donifstica), or in 

 Mynnica la-riiwdis, both of wliich have stings, though this 

 seems no bar to its presence, as the honey ant has also 

 a sting. 



♦ 



BOTANICAL STUDIES.-VI. 



SELAGINELLA. 



By A. Vaughan Jennings, f.l.s., f.g.s. 



THE life-history of the little spleenwort, which 

 formed the subject of our last study, ' showed that 

 in the true ferns the plant with which we are 

 familiar is the real Sporophyte generation. The 

 fern-plant proper produces no Archegonia and 

 Antheridia, such as our previous examination of the moss 

 might have led us to expect ; but a large number of 

 similar spores are developed in simple spore-cases on the 



Fig. 2.- 



Grizzard of Ant {Lasius 

 niger)y. 100., 



* KNOWLEDGE, September, 1898. 



