970 SUMMARY OF CURRENT RESEARCHES RELATING TO 



variously disposed, on scales on tho wings, in thoracic pouches, in 

 pouches on the posterior wings, &c. There arc small odoriferous 

 scales, usually occurring. They are generally protected, often 

 associated with tufts of hair, which diffuse fragrance. Tho various 

 arrangements in several German and tropical forms are hriefly noted. 



Posterior Sac-like Appendages of some Larval Nemocera.* — 

 Ilerr A. Jaworowski has studied tho development, structure, and 

 function of the above organs on the larvae of Corethra plumicornis, 

 Culex pipiens, Chironomus plumosus, and Janypus variegatus (?), and 

 notes (1) that they are branchiae which atrophy at a later stage; 

 (2) that the external membrane is not amorphous, nor hypodermic, 

 but is composed of a compact layer of elongated protoplasmic 

 filaments. 



Respiratory System of Odonati t — Signor D. A. Eoster has 

 studied the respiratory system of the aquatic larvae of various 

 Odonati, and especially of JEsclma cyanea. He discusses in detail 

 the central and peripheral disposition of the principal tracheae, and 

 the rectal lamellae by means of which the oxygen is absorbed from 

 the water. The peculiar papillary terminations on the rectal tracheae 

 are described and figured. He notes how the oxygen taken in by 

 osmosis in the intestinal branchiae is distributed and absorbed by the 

 general tracheal system, and how the change of the respiratory 

 organs takes place slowly after five or six days of continuous modifi- 

 cation. 



Aphis rumicis and a Fungus destructive of the Aphis.J— The 

 Rev. W. Houghton and Mr. W. Phillips have a notice of Aphis 

 rumicis, which in the autumn of last year attacked the mangel- 

 wurzel crops in Shropshire. This aphis becomes infested by a red- 

 coloured fungus closely allied to the Empusa muscse. It may be 

 called Entomophthora ferruginea n. sp. 



Mallophaga in the shafts of Birds' Feathers. §— M. E. L. Troues- 

 sart finds that in some cases Mallophaga penetrate into the shaft of 

 birds' feathers, and live there in the same way as do the acarine 

 Syringophila. His attention was directed to this mode of life by 

 the perforations which he detected on some of the large wing feathers 

 of a Numenius arquatus. 



Palseozoic Insects. || — Over the Palaeozoic vestiges of insects not 

 a little controversy has already arisen. Dr. F. Brauer has lately 

 criticized the views of Brogniart and Scuddcr on the nature of these 

 primitive insects, and has sought to establish the following con- 

 clusions : — (1) The Palaeozoic insects do not in any way contradict 

 the ordinary opinion as to the derivation of insects from a type like the 

 Tltysanura. (2) They do not form a special order — the common 



* Cosmos Pulon., v. p. 204. Cf. Arch. Slav, de Biol., i. (1886) p. 222. 

 t Bull. Soc. Entom. Ital., xvii. (1885) pp. 260-8 (2 pis.). 

 % Ann. and Mag. Nat. Hist., xviii. (1886) pp. 1-6 (1 pi.). 

 § Comptes Rend us, ciii. (1886) pp. 165-7. 



|| Ann. Naturh. Museum Wien, i., Heft 2. Cf. Naturforscher, xix. (1SS6) 

 pp. 331-2. 



