EXTRACTS FROM FOREIGN PERIODICALS. 45 



membrane, there was a cylindrical body, seven inches in length, and about one 

 inch thick. This organ was white, and of a mammillary structure, porous, and 

 resembling a cellular sponge. With gentle pressure it emitted a milky fluid. On 

 the outside of this organ, I observed heads of young Serpents about an incli in 

 length. They were so small and tender, that in extracting them from their cells, 

 I crushed several ; but I succeeded in getting out a few, measuring from three to 

 six inches in length, and of the thickness of a knitting-needle. The Serpent was 

 killed with a pointed stake, which passed across the body, bruising part of the 

 organ containing the young. These latter were also injured, so that I could not 

 ascertain their exact number ; but there were between ten and twenty. They 

 had evidently never left their mother's body, nor were they capable of feeding on 

 anything but liquids, and even that not of their own accord. I therefore con- 

 cluded that the mammillary organ was the place in or near which they com- 

 menced their existence, and which, at a certain stage of their growth, supplied 

 them with nourishment. The following fact tends to confirm this opinion : — 

 Several years afterwards I examined a number of young Serpents of a different 

 genus, and found them much larger, and considerably stronger and more lively 

 than those taken from the body of the water serpent. — Dr. Silliman's American 

 Journal, vol. xxiv. 



5. — The True Cause of the Sound produced by Insects in Flying. — 

 It is generally believed, both by men of science and by the vulgar, that the " buz- 

 zing" of insects in flight is caused by the vibration of their wings. Dr. Hermann 

 Burmeister, in a paper on this subject published in the Annalen der Physik 

 und Chemie, combats that notion, and states, that it is really produced by the 

 contact of the air with certain air or respiration holes in the thorax, the sound 

 being assisted and modified by the motion of the wings, and being produced much 

 in the same manner as the notes of a flute. The Doctor proves that the wings 

 alone cannot be looked to as the cause of the humming, by its being still heard 

 when the wings are entirely removed, and the insect is held by the legs ; and he 

 demonstrates that the above-mentioned air-holes are the true whistles — for to such 

 they may be compared — by the fact, that when those tubes are filled with gum, 

 and the insect flies away, the sound is no longer heard. True, the animal can 

 only survive this operation a short time, from the impossibility of breathing ; but 

 Dr. Burmeister considers that the experiment satisfactorily points out the truth 

 of his views. In these opinions— -facts we might call them — Dr. B. is opposed by 

 M. Silbermann, and supported by MM. Dumeril, Schelver, and Chabrier. — 

 Those who desire a more minute account of Dr. Burmeister's discovery, are 

 referred to the German work, Annalen der Physik und Chemie, vol. xxxviii., or 

 to the translation of the Professor's paper, in Taylor's Scientific Memoirs, vol. i. 

 p. 377. 



