374 SUMMARY OF CURRENT RESEARCHES BELATING TO 



ventral. All of them, with the exception of the alse cordis, which 

 subserve the function of circulation —and they are more numerous 

 than is generally supposed — take part in respiration, and consequently 

 in the production of heat, which is so important a function in the 

 economy of the bee. The mechanism is more complicated than is 

 ordinarily believed, for when the abdomen shortens or elongates the 

 dorsal and ventral surfaces approach or separate from one another ; 

 in other words, the abdomen dilates or contracts along three axes to 

 admit or expel air by its stigmata. 



Flight of Insects.* — Dr. Amans has a second essay f on the flight 

 of insects, in which he describes the organs of the Orthoptera. 



Aphides of the Elm.J — J. Lichtenstein records some observations 

 which have enabled him to establish the fact of the migration of the 

 Aphides of the elm (Tetraneura ulmi) to the roots of grasses, and 

 their return to the trunks of the trees in autumn. 



j8, Myriopoda. 



Head of Scolopendra.§ — This memoir (in English) treats in 

 detail of the external anatomy of the parts of the head in Scolopendra 

 suhspinipes Kohlr., as most typical of the Chilopods. The details 

 appear to have been worked out with care, while the drawings seem 

 to have been very carefully made by the author, and beautifully 

 engraved. 



In the course of his lengthy review of the works of his pre- 

 decessors, the author criticizes and disproves Newport's views that the 

 head of the Chilopods is composed of eight subsegments. Four pages 

 of the memoir are devoted to an elaborate and useful tabular view of 

 the opinions of forty-six authors as to the morphology and nomen- 

 clature of the mouth-parts. Dr. Meinert gives a new explanation 

 and nomenclature of the mouth-parts. He also claims that they are 

 analogous with those of biting insects, or, to use his own words, " it is 

 purposed to serve me to show the coincidence of the head of Chilopoda 

 and its parts of the mouth with the head of the Insect and its parts 

 of the mouth, especially in the Orthoptera, that is to say, in insects 

 with free biting parts of the mouth, and four pairs of these parts or 

 four metamers in the head." He does not regard the antennae and 

 the antenna,l segment as homologues of the other mouth-parts and 

 segments. In his own words, " The real head then must be said to 

 consist of the three foremost metamers, together with their exponents 

 or limbs ; that is to say, the labium, the maxillae and the mandibles, 

 and besides of the lamina cephalica, which latter, as well as its 

 appendages, the antennse, I by no means can consider to be homo- 

 nomeous with the other metamers of the body and of the head, and 

 with their exponents." 



* Eev. Sci. Nat., iii. (1883) pp. 121-39 (2 pis.). 



t See this Journal, iii. (1883) p. 832. 



i Comptes Rendus, scvii. (1883) p. 1572. 



§ F. Meinert, ' Caput Scolopendrse. The Head of the Scolopendra and its 

 Muscular System,' 77 pp. and 3 pis. 4to, Copenhagen, 1883. See Amer. 

 Natural., xviii. (1884) pp. 270-2. 



