88 



HARDWICKE'S SCIENCE-GOSSIP. 



marine glue. The marine glue requires careful 

 selectionj as the glue usually sold contains particles 

 of the . undissolved materials, which are visible 

 under the microscope. However, having obtained 

 the right sort, cut thin slices, lay them upon the 

 glass and meltover a flame ; when thoroughly melted, 

 drop the specimen (the polished surface being down- 

 wards) into it, aud press out the air-bubbles. When 

 the air-bubbles appear between the glass and the 

 polished surface, they must be got rid of, otherwise 

 it is useless to proceed ; for long before the spe- 

 cimen is thin enough to show structure, the coal 

 over the air-bubble comes away, leaving a hole. 

 If they be not present, the preparation may be 

 proceeded with, first reducing it on sandstone, and 

 then finishing it with pumice-stone; and after 

 scraping away the superfluous marine glue, mounting 

 in Canada balsam aud covering in tiic usual way. As 

 the grinding goes on, it must be frequently examined 

 under the microscope. The first to appear will be the 

 spore-cases, aud a careful coutiuuancc of the grinding 

 will finally render the spores visible. Spores and 

 spore-eases are to be found in every successful pre- 

 paration of coal ; but their relative proportions aud 

 degrees of preiCrvation vary considerably; thus 

 Wigaa cannel almost entirely consists of spores, very 

 fewspore-eases'; Bradford coal, spores and spore-cases 

 iu nearly equal proportions ; Silkstone coal, spore- 

 cases few and much compressed, spores in abundance ; 

 Moira coal, Leicestershire, spore-cases beautifully 

 preserved, and in some spores in situ ; while coal 

 of Australia consists almost entirely of spore-cases. 

 [The impurities in the marine glue may be separated 

 from it by t}ing it in a piece of linen or flannel, 

 immersing it in hot water, and squeezing it vv'ith a 

 piece of wood.] — F. K. 



A Hint to Microscopists.— I would suggest 

 to those who are seeking entomological objects, 

 that the empty pupa-ca^es of butterflies and moths 

 would be found to furnish some nice slides. Small 

 portions of the envelopes which encase the an- 

 tennae and legs could be exhibited iu their entire 

 state; of the shell which wmps over the wings 

 and body, sections might be mounted as opaque 

 objects, or, in many instances, I should think, thin 

 slices would be found to be transparent. But the 

 student niust not suppose, should he chance to 

 find one of the pupaj or clirysalids wiiieh are be- 

 spangled with metallic markings, that when tlie 

 insect within has emerged he will get a splendid 

 slide therefrom, for these disappear when tiie case 

 has lost its tenant. — /. B. S. C. 



"In the presence of the Alps, no worldly autho- 

 rity can preserve its lying prestige ; the only sove- 

 reignty which there exists is that of reason, truth, 

 aud eonscieuce." — " T/ie Mountain," //-om the Frencli 

 of MicJicltt. 



ZOOLOGY. 



Blind EisHES. — In the Eebruary number of the 

 American Naturalist, Professor Putnam adds an 

 important fact to his interesting paper on the above 

 subject, obtained from Dr. Hartriug. He states 

 that a specimen of one of the blind fish, Typhlichthys, 

 was placed in a jar of spirits, when shortly after- 

 wards eight young fish were observed. Their birl h 

 was due to the sudden immersion in alcohol. 

 When these young flbh were examined with a 

 magnifyiug-glass, they were seen to be totally de- 

 prived of eyes ! It will be rcmem.bered that in the 

 adult state these fish had their eyes aborted. 



Parasite on Pieuis Baf^ (the small Cab- 

 rage BuTTERrLx) IN CANADA.* — The uews of the 

 appearance of a;i effective parasite on P. Uapa will, 

 we doubt not, be hailed with delight by our Lower 

 Canadian friends and the gardeners of the North- 

 Eastern States. Mr. P. S. Sprague, of Boston, 

 Massachusetts, has kindly sent us several specimens 

 of both sexes of this new arrival, respecting which 

 he writes as follows :— " The F. Rapce chrysalis 

 parasite proves, on exami'iation by Dr. Packard, to 

 be the introduced Flcroijialus piiparum. My son 

 gathered about fifty of tlie chrysalids, every one of 

 which was infested, as many as forty specimens 

 coming from a single one. The female walks over 

 the chrysalis, feeling with her anteuncefora suitable 

 place to insert her ovipositor, aud when found, 

 drills a hole, wdiich takes upon an average one 

 minute in tiu:e." The following excellent com- 

 munication by Mr. Sprague's son, who bids fair to 

 become an eminent entomologist, we copy from 

 the Rural New Yorker. " A new Enemy to the 

 Cabbage-worm : — Although I am a little boy, 

 I think I can write something which will please the 

 old folks. Almost everybody who raises cabbages 

 has had a great many destroyed this year by a little 

 green caterpillar, and I suppose they have seen a 

 new white butterfly, called the Pieris Bapa, flying 

 round them. This butterfly lays a little white egg 

 on the leaves, which iu a few days hatches out a 

 little green caterpillar, which eats until it grows 

 about an inch in length ; then it goes aud hunts up 

 some sheltered place where it can go into a chrysalis. 

 I was looking for some chrysalids for my father, 

 flhen I saw a little fly walking all over them ; by- 

 aud-by it made a little hole in the chrysalis to lay 

 its eggs iu. Tliis fly is almost one eighth of an inch 

 long ; it is of a golden colour. Some of the flies 

 have yellow legs and others have dark onts; they 

 have four wings ; the body is pointed at the end : 

 there are about fifty of these flics in a chrysalis. 

 The chrysalis looks as if it were all right ; but if you 



* This peet was introduced into Canada from Europe a few 

 years ago, and has multiplied so rapidly as to have become 

 already a source of serious uneasiness. — En. S.-G. 



