82 



SCIENCE. 



[Vol.. I., No. 3. 



Insects. 



Histology of insect -wing-muscles. — The mem- 

 oir of G. V. Ciaccio, to appear shortly in the Meiiiorie 

 dell' accademia di Bologna, may be thus summarized: 

 III most insects the wing-mnscles may be decoinposed 

 into fibrillae (in others, into striated fibres: Sphinx, 

 LibelUila, etc.). In the former case the fibrillae are 

 united into bundles of various sizes by a cementing 

 substance, in which the nuclei lie either both in the 

 interior and upon the surface of the bundle (Hydro- 

 philus, Uytiscus), or upon the surface only (flies). 

 The bundles are held together by tracheae, and some- 

 times also by fat-cells'. In the cement are further 

 always found distinct particles (Auberl's masse yru- 

 meleiise interfibrillaire], which do not occur in the 

 other muscles. The fibres are composed of fibrillae, 

 anil have nuclei either upon the surface (Cicada) or 

 In the middle (Libellula). In some insects the fibrillae 

 are arranged as in a folded lamella, the leaves of the 

 folds running out from the centre of the fibre towards 

 the surface, seen in cross-sections. The nerve-fibres 

 terminate in motor plates (probably several for each 

 fibre), consisting of a granular basal substance, in 

 which are embedded the ramifications of the axis- 

 cylinder. The wing-muscles are more readily disso- 

 ciated into fibrillae than those of the rest of the body, 

 from which they are further diflferentiated by the 

 absence of a true sarcolemma. — (Arch. ital. biol, ii; 

 131.) c. s. M. [247 



Curious gall of a Trypeta. — Weyenbergh found 

 in the Argentine Republic, on the terminal bud of a 

 Heterothalamus, what resembled the fi-olh which is 

 secreted by the ' frog-spittle' insect, Cercopis spuma- 

 ria L., but which, on touch, proved to be more sub- 

 stantial, or like a raspberry in texture, and on drying 

 became tough like paper. Concealed by the froth was 

 found a larva, which underwent its ti'ansformations 

 within the same covert, and finally issued as a fly, 

 which he names Trypeta (Icaria) Scudderi. The 

 formation of the froth was observed in a larva jilaced 

 on paper; it pressed its terminal segments together 

 with nearly rhythmical movements, and so I'epeatedly 

 squeezed little drops of clear fluid from the anus, 

 which collected by and by into a frothy mass. — ( Ver- 

 handl. zoul.-bot. r/esellsch. Wien, 1882, 363.) [248 



{Economic entomology.) 



Effect of pyrethrum upon Plusia brassicae. — 

 Mr. Howard finds that the rate of pulsation of the 

 heart of the larva is greatly increased at once, and 

 falls but little before death. — (^Imer. nat., Decem- 

 ber, 1S82.) J. H. c. [249 



The cluster-fly. — A fly which has proved to be a 

 great nuisance to housekeepers by entering dwellings 

 in the fall of the year, and assembling in large num- 

 bers in beds, under table-covers, behind pictures, and 

 elsewhere, is determined by Dr. Kiley as Pollenia 

 rudis Fabr. — (Amer. nat., Jan., 1883; cf. Psyche, iii. 

 378.) J. u. c. [250 



Wheat-stalk Isosoma. — Professor French ob- 

 served, that in two wheat-fields which were in wheat 

 last year ninety-three per cent of the stalks were in- 

 fested by this insect; in one field which was in clover 

 last year, not more than five per cent were infested. 



— (Amer. nat., Jan., 18S3.) j. H. c. [251 

 Promoting locust ravages. — It is estimated by 



Mr. J. P. Brown, that during the winter of 1874 one 

 thousand car-loads of birds were destroyed and shipped 

 to eastern markets from points west of St. Louis, Mo. 



— [Psyche, m. 'i^Q.) j. h. c. [252 

 Buckeye leaf -stalk borer. — Mr. E. W. Claypole 



describes the habits of a new tortricid which Fernald 



names Steganoptycha claypoleana. — ( Psyche, iii. 

 804.) J. H. c. [253 



Habits of Thrips. — A species of Phloeothrips ob- 

 served by Mr. Herbert Osborn in fruit-ldossoms were 

 doing much damage by injuring the styles, and thus 

 preventing fertilization. — (P.syche, iii. .3()4. ) 



Although the species of Thrips are doubtless to a 

 certain extent injurious to plants, Mr. Pergande be- 

 lieves that they feed chiefly upon nectar, and that 

 they assist in fertilizing the plants they infest by car- 

 rying pollen. One species of Thrips preys upon the 

 red spider. — (Psyche, iii. .381.) J. H. c. [254 



VERTEBRATES. 



The theory of the opening- t-witch (Oeffnungs- 

 zuckung). — An extended study of the opening- 

 twitch leads TIgerstedt to the conclusion that the 

 cause of it, and of the phenomena accomp.anying it 

 in the nerve, lies in the polarizalion current, and, 

 with some exceptions, in changes in the normal nerve 

 curient. The twitch due to a sudden decrease in (he 

 intensity of the polarizing current was not examined, 

 so the above conclusion only applies to cases in which 

 that curient was comjiletely broken. — (Mitth. physiol. 

 lab. Carol, inst. Stockh., ii. heft.) H. n. m. [255 



Fish. 



The development of the hypophysis in Petro- 

 myzon planeri. — Recent investigations by Prof. 

 A. Dohrn have led to a different interpretation of 

 the development of the hypophysis of Cyclostomes 

 from that given by W. B. Scott or that of Balfour. 

 The former stated in effect (Morphol. jahrb., vii. 108) 

 that the rudiment of the organ in question was un- 

 paired. Its first appearance is marked by a slight 

 depression above the mouth, which we may regard 

 as the comnuin invagination from which the nasal 

 pit and hypophysis arise. Balfour states (Comp. em- 

 bryol., ii. 358), "I have observed a slight diverticu- 

 lum of the stomodaeum, which I believe gives origin 

 to it." 



Dohrn holds, that his own more recent observations 

 of the past summer show that the hypophysis arises 

 as an independent invagination of the ectoderm be- 

 tween the nasal and oral invaginations. It has no 

 connection with the latter, in that the upper lip is 

 developed between the oral invagination and hypoph- 

 ysis. — (Zoolorj. anzeiger, 'Nov. 6, 1882.) j. A. B. [256 



Muscles of the raccoon's limbs. — Dr. H. Allen 

 compares them with those of Felis domesticus. 

 Tiicef^ and some others undergo imperfect planal 

 cleavage, showing imperfect differentiation; the 

 Tiumber of nerves is variable, being most abundant 

 in the less specialized muscles; the latter have more 

 nerves in Felis than in Procyon; triceps and some 

 others when normal in Procyon represent abnormal- 

 ities in man; some are identical in both; others seem 

 to be beyond the limits of variability in man. — (Proc. 

 acad. nat. sc. Philad., lSS2,llo.] r. w. x. [257 



Myology of Proteles. — M. Watson points out 

 the characteristics of the muscles of Proteles crista- 

 tus, and agrees with Prof. Flower that the s]3ecies 

 should be placed in a separate family, allied to Hyae- 

 nidae and Viveridae but more closely to the former. — 

 (Proc. zodi. soc. iond., 1882, .579.) F. w. T. [258 



Singing mice. — Herr Struck gives some notes 

 upon a singing mouse which lived in captivity ten 

 months. He inclines to doubt Cohen's opinion, that 

 the musical tone is due to disease of the throat, and 

 thinks that the mice may die in consequence of 

 eating too rich food. — (Arch. ver. freunde nat. 

 Meckl., XXXV. 117.)— P. W. t. [259 



