344 



Gt^ANINGS m BEE ctjttUEE. 



May 



bee. The large size of these glands seemed to indi- 

 fcate that they had some other purpose than to se- 

 crete the saliva. It seemed possible that they might 

 secrete the larval food. Fischer described these 

 glands a year later, and expressed the same opinion 

 as to their function. Leuckart then declared that he 

 tad taught this theory to his students for years. 



I then thought this theory very plausible, and 

 i^robably the true one; but 1 expected further 

 Study and a closer examination, but expected in 

 vain. V. Siebold, and probably Leuckart as well, 

 forked on other problems. I supposed a micro- 

 Scopib e±aminiition of the secretion from these 

 g-laiids would prove the identity of the same with 

 the food bf the larva?, but no such proof was forth- 

 bomirtg. It may bb said, that there is too little of 

 the product of the glands for analysis. But just 

 this Seems to indicate that the comparatively small 

 g-lands can tiot secret so large a quantity of larval 

 food. 



(This view alone would not count for much. There 

 is too little nectar in most flowers for a successful 

 analysis; yet the bees gather pounds of it in a day. 

 Supposing that the lower head glands of a single 

 bee do not secrete enough material for successful 

 analysis at any one time.yet thousands of bees might 

 do this with the whole day before them, and have 

 enough left to feed all the larvie.) 



In 1880, Schonfeld published his theory, which 

 seemed to me nearer the truth. 



Years before, Leuckart desciibed the larval food 

 as agranular, milky, uniformly colored fluid contain- 

 ing many microscopic corpuscles, similar oridentical 

 with the blood corpuscles, and with the corpuscles 

 found in the chyle, or digested food, in the true 

 stomach, which chyle passes directly through the 

 walls of the stomach by osmosis. Wolff states that 

 the blood corpuscles originate in the stomach. 



Analogy of the mammalia favors the gland theory 

 of Leuckart. It seems plausible that the young bee, 

 like the young calf, is fed with milk; yet not so 

 plausible when we remember that the larva is not 

 a young bee. I would rather compare the larva 

 to the embryo of a mammal, and this is nourished 

 directly from the blood. The chyle of bees is, in 

 fact, identical with their blood, and contains every 

 thing necessary to build up the body of the bee; 

 so it seems rational and natural to suppose that the 

 chyle is the larval food. 



(Analogy is always an uncertain argument. In 

 case of animals as wide apart as the mammalia and 

 insects, it really has no force. Grant that it had, 

 even then in the case in question it would be diffi- 

 cult to say which way the argument pointed.) 



With higher animals, the origin of the chyle is 

 more complicated, and digestion is completed in 

 the small intestines. In bees, the structure of the 

 canal is different; and it is possible that chyle or- 

 iginates in the stomach. 



(Here chyle must mean the sum total of digestion. 

 With higher animals, chyle means simply the di- 

 gested fat, and is carried to the blood through a 

 special system of vessels, while the other products 

 of digestion are mainly absorbed directly by the 

 blood-vessels.) 



If the larval food and chyle are identical, of 

 course we must depend on the microscope to prove 

 it. If we examine the stomach of the worker-bee 

 we find more or less partially digested food, but no 

 chyle. 



(From the fact that, in examining many bees, 1 



have never found the granular milk-like substance 

 fed to larval beetj, was my principal reason for 

 accepting th^ secretion rather than the digestion 

 theory.) 



Schonfeld made the following experiments, and 

 hereby is explained how the chyle can be found in 

 the true stomach of the nurse-bee: 



a. Honey colored by cherry -juice is fed to bees in 

 a starving condition. 



/*. Honey colored by holly-juice is fed in same 

 manner. 



c. In like mannei-, honey mixed with pollen of the 

 white lily, which is easy to distinguish with the 

 microscope, was fed. 



After feeding, in eabh case the contents of the 

 stomach, and the larval food, were carefully ex- 

 amined with the microscope, tn every case the 

 food in the bells with larva? was the same milky 

 granular substance, with no color, nor any lily pol- 

 len. This lal-Vai food, then, could not consist of 

 chyme or the material from the honey-stomach. 



Every hour a nurse-bee was examined, and the 

 process of digestion noted. The color was seen to 

 fade out, <md true chyle was found, differing in no- 

 wise from the food given to the larv(V. While in the 

 intestine, red and dark-colored excrement, mixed 

 with pollen-husks of the lily, were plainly evident. 

 Many bees were caught, just about to feed the larvce, 

 and the chyle was found in eaclt case. 



(This, of course, is crucial. Not finding chyle, like 

 larval food, in the stomach, does not prove its uni- 

 versal absence. Finding it once proves its ex- 

 istence. Granting the fact, the conclusion must 

 follow.) 



SALIVARY GLANDS OP BEES. 



All mature bees— workers, drones, and queens — 

 possess— 



I. The upper head salivary glands, and 



II. The thoracic salivary glands. 

 Besides these the worker-bees have 



III. The lower head salivary glands. 



Glands I. and II. have a common ending at the 

 base of the ligula, in the groove formed by the 

 paraglossfc. This secretion can, as the tongue is 

 extended, flow into the groove and wet the ligula, 

 but can go no further, because the ligula, or suck- 

 ing-tube, is no fountain-pump, and the larva has 

 no sucking-arrangement to draw this out. 



(A stronger argument, perhaps, lies in the fact 

 that drones and queens also have these glands, and 

 surely they do not feed the larva?. No one can 

 think that these are the milk-glands, even if milk- 

 glands exist.) 



The secretion from glands I. is oily; that from 

 glands II. watery, which would indicate that they 

 possess a different function. 



The function of the sucking-apparatus will show 

 that the saliva is necessary to wet the ligula, and 

 so make it possible that the nectar can ascend. It 

 would require too much space here to explain the 

 function of the sucking-apparatus, which is a mis- 

 nomer, as bees neither suck nor lick. 



(Very likely the saliva, like our own, may serve 

 to aid in keeping parts moist; but from the size of 

 the glands, and quantity of the secretion, this, as 

 in our own case, must be incidental. I think our 

 friend is surely mistaken in his last assertion. I 

 think I have shown that bees do both suck and lick.) 



If bees do change nectar more than to evaporate 

 it— that is, if they change the kind of sugar (I am 

 not sure that they do), then it is probably done by 



