244 PEOGTRESS OF MICROSCOPICAL SCIENCE. 



of tlie Proceedings of the Zoological Division of the third meeting of 

 the Russian Association of Naturalists, at Kiew, is an abstract of a 

 paper by Ouljanin on the development of the sting of the bee. The 

 author describes but two j)airs of imaginal disks, while three were 

 discovered and described by the undersigned in 1866. The author 

 homologizes the elements of the sting with the feet, as had already 

 been done by me in 1871. Soon afterwards Dr. C. Kraepelin pub- 

 lished an elaborate article on the structure, mechanism and develop- 

 mental history of the sting of the bee. In speaking of the origin of 

 the sting,* he only refers to Ganiu's observations made in vol. xix. of 

 the same Joui'ual (1869). Dr. Kraepelin seems to have overlooked the 

 writer's papers t on the origin of the sting of the bee and ovipositor of 

 other insects (^schna and Agrion) published in 1866 and 1868, the 

 observations and drawings having been made in 1863." 



The Mouth of the Dragon-fly. — Mr. Packard has also the following 

 note in the same number of the ' American Naturalist ' as the above 

 paragi'aph is taken from : — " An important article on the mouth jjarts 

 of the dragon-fly, Perl^e and allied forms {Orthoptera ainphihiotica), is 

 published by Dr. Gerstaecker, in the memorial volume of the Cen- 

 tennial Celebration of the Society of the Friends of Science in Berlin, 

 1873. The author describes and figures the palpi of the dragon-flies. 

 They possess a one-jointed maxillary palpus, and 2-jointed labial 

 palj)us, which are not however in the maxillas palpiform, but con- 

 stitute a simple lobe (galea of Burmeister, Erichson and Eatzburg). 

 In Hagen's ' Synopsis of Neuroptera of North America ' (1861) it is 

 stated ' mouth not furnished with palpi.' This statement, which is 

 morphologically inexact, was copied in the ' Guide to the Study of 

 Insects.' It will be corrected in the fifth edition of the latter, as it 

 was unfortunately too late to correct the statement in the fourth 

 edition, now passing through the press, except in a few words in the 

 preface." 



The Plan of Descent of the Animal Kingdom.^The following is 

 given as a rude outline of the plan sketched out by Professor Haeckel. 

 Regarding the sponges as consisting of two layers of cells, surround- 

 ing a body cavity, somewhat as in the Hydra, Haeckel comjjares the 

 sponge to the embryos of the higher animals, both vertebrate and 

 invertebrate. In his view the germ of all animals, and the adult of 

 such a simple form as Hydra, may be reduced to the simjjle form of 

 the young of a calcareous sponge which he calls Gastrula. " The 



* P. 320, vol. xxlii., 1873. 



t " Observations on the Development and Position of the Hymenoptera, with 

 notes on the Morphology of Insects," ' Proceedings Boston Society, N. H.,' 

 published May, 1866. " On the Structure of the Ovipositor and Homologous 

 Parts in the Male Insect," ' Proceedings Boston Society, N. H.,' vol. xi., published 

 in 1868. 'Guide to tlie Study of Insects,' 1869, pp. 14, 536. " Eml)rjological 

 Studies on Diplax, Perithemis, and the Thysanurous genus Isotoma," ' Memoirs 

 Peabody Academy of Science,' 1871, p. 20. Here the spring of the Podm-idaj is 

 homologized with a pair of blades of the ovipositor of the bee, &c., and the 

 ovipositor regarded as homologous with the si^inuerets of sjiiders and abdominal 

 feet of myriapods. 



