90 



KNOWLEDGE 



[May 1, 1891. 



■which is much more complex than might have been 

 imagined. The accompanying figure shows the long 

 tubular poison-gland which passes its secretion, consisting 

 chietly of formic acid, into the large reservoir at the base 

 of the sting ; the two lancets the latter contains may move 

 either simultaneously or alternately, and at each stroke the 



Bee's Sting asd Poison-Gland. 



poison is forced into the woimd with considerable energy 

 through canals in the lancets themselves, and out at the 

 openings between the barbs. Though the queen rarely 

 stings a human being, yet the writer's experience shows 

 that she can do so if necessary. He states also that she 

 can withdraw her sting more easily than the workers, by 

 mo%-ing round and giving the barb a spiral motion ; this, 



Dorsal Vessel or "Heart" of Bee. 



he maintains, the worker could do also, but that she is in 

 such a hurry to get off that she does not give herself 

 time, but tears herself away, leaving the sting and its 

 appendages behind her. Mr. Cowan has adopted the 

 striking and effective device of showing different systems 

 of organs separately in .situ on the dark background of the 

 body ; one of these illustrations, e>diibiting the dorsal 



vessel, or " heart " of the bee, is here appended ; the 

 small explanatory diagram added shows how the blood 

 enters by the side openings of this valvular tube, and is 

 propelled towards the head. 



No subject IS more debateable than the functions of 

 antennae, and hence much interest attaches to the chapter 

 dealing with the researches that have been made into the 

 structure and function of the tactile hairs, and of the 

 curious sensory pits in these organs in the bee, which 

 have by some authors been considered to be smell hollows, 

 and by others an auditory apparatus. The accompanying 



Salivary Glands. 



figures of the salivary glands of the bee will give an idea 

 of the neatness with which the histological illustrations 

 are executed. Mr. Cowan has made many measurements 

 of the cells of the comb, with the view of testing the 

 accuracy of commonly-received notions as to their extreme 

 regularity, and he finds that frequently considerable devia- 

 tions fi-om the normal size and shape of the ceUs occur. 

 Following Miillenhofi', he maintains that " the complexity 

 and apparent accuracy of the structure is not in the least 

 owing to the development of a mathematical instiact in 

 bees, or artistic dexterity, but simply to physical laws 

 dependent on their method of work," the cells behaving 

 " mutually like soap-bubbles, which when isolated are 

 round, but, if touching each other, where imited the film 

 forms a perfectly flat w-all." One or two misprints occur 

 in the technical terms, as e.ij. " vasa il if-ierentia, " for 

 " rfc-ferentia," and " vesiculfe seminal-(.s " for " semi- 

 nal-es." 



Celestial Motiona : a Handy Book of Astronomi/. By W. 

 T. Lynx, B.A., F.K.A.S. Seventh Edition. (London: 

 E. Stanford.) We are pleased to welcome a new edition 

 of Mr. Lyun's very handy little manual, the sixth edition 

 of which was reviewed in Knowledge for Jime 1889. In 

 the present one the information appears to have again 

 been carefully brought up to date, reference being made 

 to Schaparelli's results with respect to the rotation of 

 Mercury and Venus, and to the identity of the comet dis- 

 covered by Brooks in .July 1889 with what is generally 

 known as Lexell's comei of 1770. No notice, however, is 



