ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 443 



a new departure : that bee, trust me, will make use of this cunningly 

 devised aj)paratus, and produce honey cheaper than any competitor 

 excei^ting the glucose man, and I hope and trust may worry even 

 him." 



Alternation of Generation in the Cynipidse.* — In a paper of nearly 

 100 pages Dr. Adler deals with this subject, to which he was led by 

 the discovery that from the eggs of Neuroterus there is developed an 

 altogether different generation which has been hitherto regarded as 

 belonging to another genus (Spathegaster) ; the species studied belong 

 to four groups, Neuroterus, AphilotJirix, Dryophanta, and BiorMza. 

 Twenty-three species have their life-history described, of which four, 

 all species of the genus AphilotJirix, exhibit no alternation of genera- 

 tion ; all belong to the North German fauna. 



In the third chapter the author deals with the formation of the 

 galls, and devotes the fourth to an account of the organs of the insect 

 which are adapted for the purj)ose of causing them. The process of 

 oviposition appears to consist of three stages ; in the first, the canal 

 is formed by the sj)ine at first passing under the covering scales at 

 the base of the bud, and then turning into the centre of its axis ; the 

 egg, being seized between the sette of the spine, is j^assed below this ; 

 when the tip of the spine is removed from the canal, the ovarian body 

 enters into it, and is pushed forward by the spine until it reaches to 

 the end of the canal ; the ovarian stalk which occupies the canal is 

 believed to have a respiratory function. 



The reproductive organs in the two generations are reported to be 

 very similar in character ; the ovaries have the same structure, and 

 contain from six to twelve eggs ; as a rule, the agamic generations 

 have a larger number of eggs than the sexual ; the muscular vagina 

 and its appended glands are alike in the two generations ; on either 

 side there is a simple glandular tube, the secretion of which probably 

 serves as a fluid for the conveyance of the spermatozoa, and these 

 glands are, in consequence, better developed in the sexual than in the 

 agamic forms. It is curious to observe that there is a receptaculum 

 seminis in the asexual generations, although, of course, it is to some 

 extent rudimentary. 



The period of the development of the larva varies in the two 

 generations ; being much shorter in the summer than in the winter 

 one. 



(1) The larva may be developed in the same year, and become 

 completely developed, remaining for a year or more in the gall 

 (ApMlotrix). 



(2) In the first year the larva only attains to a certain grade of 

 development, in which it passes through the winter, and is only fully 

 developed in the second year ; or 



(3) The larva may remain for a long time in a very early stage, 

 and only become more fully developed when the gall falls away 

 (Neuroterus). 



Dr. Adler believes that the present agamic form was identical with 



* Zeitschr. f. wiea. Zool., xxxv. (1881) pp. 151-247 (3 pis.). 



