ISi 



HARDWICKE'S SCIEN CE -GOS SIP. 



DiATOMACEOUs Frtjstules. — Professor H. 

 Smith states in the " Lens," that he believes all 

 cliatomaceous frustules to be " siliceous boxes," 

 with either one portion (the cover) slipping over 

 the other, as in Finnularia, or with edges simply 

 opposed, as in Fragilaria. If we take a frustule of 

 Melosira, it may be compared to a pill-box, one 

 portion slipping on to the other. The great majority 

 of diatoms are thus constituted. 



ZOOLOGY. 



Birds' Geographical Range.— There] are cer- 

 tain though somewhat indefinite limits to the range 

 of birds ; limits governed, however, by climate 

 rather than by physical boundaries. Thus the 

 Dusky Albatross {Diomedea fuliginosa) was ob" 

 served by Captain Beecliey to be numerous in the 

 Atlantic, from the Rio de la Plata lo the latitude of 

 51° south, when it suddenly disappeared ; but after 

 rounding Cape Horn, the species again occurred at 

 the very same latitude of 51°, and continued nu- 

 merous all up the coast of Chili. The Tropic Birds 

 (Phaethon), in like manner, as their name imports, 

 chiefly frequent the ocean within the tropics ; and 

 according to the statements of all voyagers, are 

 very rarely seen beyond the parallel of 35°.— G^osse, 

 " The Ocean." 



A Curious Insect.— 1 had an opportunity of 

 observing a curious insect which inhabits trees of 

 the Fig family, upwards of twenty species of -which 

 are found here. Seven or ^ eight of them cluster 

 round a spot on one of the smaller branches, and 

 tliere keep np a constant distillation of a clear fluid, 

 which, dropping to the ground, forms a little puddle 

 below. If a vessel is placed under them in the 

 evening, it contains three or four pints of fluid in 

 the morning. A similar but much smaller homo- 

 pterous insect, of the family Cercopidte, is known in 

 England as the Froghopper {Aphrophora sptcmaria)y 

 when full grown and furnished with wings ; but 

 while still in the pupa state it is called Cuckoo-spit 

 from the mass of froth in which it envelops itself! 

 The African species is five or six times the size of 

 the 'Eix\»\h\\.— Livingstone, " Missionary Travels." 



The British Association.— Great preparations 

 are being made to render the British Association 

 meeting at Brighton, on the 14th of August, a 

 complete success. Philosophical naturalists will 

 expect a treat in Dr. Carpenter's inaugural address. 



Modern Subdivision in Science.— " That our 

 ancestors did not subdivide as much as we do, was 

 something of their luck, but no part of their merit. 

 Simply as subdividers to the extent which now 

 prevails, we are less superficial than any;former 

 age. But is it better to be a profound student or 



[ a comprehensive one ? In some degree this must 

 depend upon the direction of the studies, but, 

 generally, I think, it is better for the interests of 

 knowledge that the scholar should aim at pro- 

 fundity, and better for the interests of the indi- 

 vidual that he should aim at comprehensiveness." — 

 Thomas De Quincey. 



Rearing Atropos (p. 20, Jan. No.).— This 

 species is often troublesome to the breeder, and it 

 is very mortifying, after having captured the noble 

 larva, to have it die upon our hands in the pupa 

 state. Naturally, the larvae descend to some depth 

 in the earth, and thus escape the effects of mud, 

 moisture, or drouglit, heat or cold. The nearer we 

 can bring their condition in winter to that which 

 they would be in if at large, the greater are our 

 chances of rearing ; and if a larva has gone down 

 for the winter in a flowerpot, or similar article, 

 the exposure of this out of doors throughout the 

 winter, in a place not too exposed, may be advan- 

 tageous. The earth with which the larvae are 

 supplied should not be too fine, nor clayey. The 

 difiiculty is, how to adjust the moisture which 

 seems necessary, so as to keep the pupa in health, 

 without bringing on any decomposition. Dryness 

 seems, in this instance, to be more prejudicial than 

 damp : in many other species, we know that the 

 pupae will thrive if laid merely upon dry moss and 

 kept moderately cool. Mr. H. N. Humphreys 

 states that he managed thus : — " A large flower- 

 pot being selected, I stopped up the hole with a 

 cork, taking care to pass a quill, open at both 

 ends, through the cork, to serve as an escape-pipe 

 for superfluous wet, and yet not being large 

 enough to allow of the escape of the caterpillar ; 

 then, having put in a layer of pieces of broken 

 pots, to secure sufficient general drainage, the pot 

 was nearly filled with light gardenfmould, a piece 

 of strong canvass tied tightly over, and tlie pot 

 plunged up to its rim in a sheltered part of the 

 garden." It being an ascertained fact that of each 

 annual brood of Atropos a certain part (nearly, if 

 not all, barren females) emerge in the autumn, 

 some entomologists have recommended the 

 "forcing-out" of any captive pupae. This has 

 now and then succeeded; much more frequently, 

 however, through lack of sufficient nicety in the 

 administration of heat and moisture, the specimen 

 is dried up.—/. R. S. C. 



Extracting Poison from the Rattlesnake. 

 — The process of extracting the poison from the 

 rattlesnake {Crotalus horridus) for medicinal pur- 

 poses whilst the reptiles were still living, has been 

 succesfully accomplished by Mr. J. C. Thompson 

 and Dr. Hayward, of Liverpool. The following was 

 the modus operandi, if any of our readers care to do 

 likewise : — The reptiles were in separate compart- 

 ments of a large case, fitted with a double lid for 



