42 



HARD WICKE ' 5 S CIE NCE- G OSSIP. 



Fans." In the January issue, the 1st Study is in 

 Vegetable Physiology, " The Protoplasmic Con- 

 tinuity ;" the 2nd in Animal Histology, " Mammary 

 Glands ;" the 3rd in Pathology, a continuation of 

 the paper on " Congestion of Kidney ;" and the 4th 

 in Marine Algae. All the parts are illustrated by 

 exquisitely drawn and coloured plates. 



New Slides. — We have received from Mr. Fred 

 Enock an exquisitely beautiful and well-mounted 

 object — the " Fairy Fly "( Litus cynipsens), forming 

 No. 7 of his capital "Entomological Sketches." 

 Mr. W. S. Anderson, Ilkeston, has sent us a box 

 containing the following interesting subjects, all well 

 mounted : water scorpion, cardinal beetle, brown 

 ant, sun beetle, larva of dragon-fly, and the nymph- 

 stage of the water-bug. 



Sections of Sponge. — Will some of your readers 

 give me advice as to cutting sections of freshwater- 

 sponge ? I mean, so as to preserve them whole as 

 they come from the microtome (the one I use is made 

 after the directions given by a medical gentleman in 

 your issue, Jan. 83, 1 think it was). Directly I dissolve 

 out the paraffine and wax, the section goes to frag- 

 ments. What I want to find is some transparent 

 medium by which I can fasten the section in the 

 slide — keep it so, while the imbedding mixture is 

 dissolved and cleared away. The microtome has 

 answered admirably for other things. I have some 

 slides of sea-sponges, cut in this microtome which are 

 very thin and well done. — "Joseph Clark. 



Preserving Polyzoa.— A new method of pre- 

 serving polyzoa and other low forms of life has been 

 discovered by Dr. A. Fottinger. Crystals of chloral 

 hydrate are dropped into the vessel of water in which 

 polypes have been placed, and in a short time the 

 creatures become insensible, when they can be placed 

 in alcohol. The advantage claimed for this method 

 is that the polypes will remain expanded, and can 

 therefore be preserved when exhibiting all their 

 beauty of structure. The chloral acts, it would seem, 

 in much the same manner as it affects higher 

 organisms — that is, as a narcotic. 



ANIMAL PSYCHOLOGY. 



Anecdote of a Spider. — Some time since, when 

 in Torquay, I saw an interesting sight which I here 

 record. A friend was requested to water some ferns 

 in a house during the absence, for a few weeks, of 

 the occupier. The ferns were in a box in a window 

 of one of the rooms of the house. A lead pipe, 

 pierced with small holes, was so arranged that on 

 turning a tap small jets of water were thrown up so 

 as to fall over the box of plants. A very large spider 

 had taken up its position at one end of the box in the 

 window, and had constructed a web of about four 



inches in diameter. Two of the jets of water rose 

 near the web and wetted it. When the tap was 

 turned, and the water flowing, the spider ran to one 

 of the jets and began to work vigorously with its legs 

 as if trying to climb up the rising stream of water ; it 

 would go back to its den and come out again, and 

 repeat the performance two or three times, now at 

 one jet, then at the other. This was done on each 

 morning for some time. The question I wish to ask 

 is this : Why did the spider do this ? My friend 

 who called my attention to it thought it came to 

 drink, as it returned each time to its den with a drop 

 of water on its body. My own impression was, that 

 as the jet of water ran through a part of the web, the 

 spider came to resist the interference, and was 

 trying to oppose the flow of the stream. — Ignore 



The Crow. — Two possible explanations occur to 

 me with respect to J. W.'s query, (i.) That the crow 

 only flew to a short distance, and therefore never 

 once took his eye off the tuft of grass, (ii.) That the 

 general locality was well known to the crow, who 

 only had to use his sense of smell to discover under 

 which tuft he had previously concealed the crust of 

 bread.— F. C. D. B. 



Migration of Birds. — How do the British birds 

 which migrate annually to far-off countries find their 

 way back ? Some people say that we must remember 

 that a bird en route flies sufficiently high in the 

 air to take what is commonly known as a "bird's- 

 eye" view of the country over which, on their journey 

 south, they traverse ; and that consequently it is only 

 the salient features that impress their memory. Well, 

 no doubt, like Darwin's theory, this is a very 

 plausible explanation, but it is not quite convincing. 

 I believe I am not misinformed when I say that 

 there exist records of birds returning to the same tree, 

 nest, or thatched roof, year after year. Now, our 

 said friends can scarcely maintain that such an 

 insignificant thing as a thatched roof or a microscopic 

 (comparatively speaking) nest is sufficiently pro- 

 minent to impress a bird with a retentive knowledge 

 of its locality. It is a well-known thing that if we 

 vibrate a certain string in our memories, the result is 

 a thoroughly connected train of thought. And 

 further I believe it is agreed that migratory birds rest 

 at certain points of their journc^y ; and therefore, why 

 should not each of these resting-points, when arrived 

 at, bring a connective idea to the bird of what will 

 guide him to his next resting-place ? Here, I suppose, 

 it will be objected that there is nothing to direct the 

 birds between the intervening spaces. Granted ; but 

 it should be remembered that the young birds 

 generally keep company with their seniors during their 

 first migrations, thereby obtaining their knowledge of 

 the course by a certain sort of apprenticeship— quite 

 sufficient (in my opinion) to give them a comprehen- 

 sive impression for these, to them, comparatively 



