94 



SCIENCE-GOSSIP. 



The United States Department of Agriculture 

 has issued a well-illustrated list of the adult tape- 

 worms of cattle, sheep, and allied animals, from 

 which it appears that domestic cattle are infested 

 by eight adult cestodes, the goat by two, the sheep 

 by eleven. 



Sensitiveness of the Eyes of Frogs. — 

 Referring to Mr. Perks' query as to why snakes 

 and fishes are able to dispense with the sensitive- 

 ness to touch on the eyes, which is so character- 

 istic in the higher orders, the integument, which 

 covers the heads of fish and reptiles, is continued 

 over the eyes and gives protection to these organs. 

 The eye itself is beneath this integument and is 

 thus effectually protected from outside influence. 

 Snakes are devoid of eyelids, and it is this which 

 gives these creatures the peculiar stony stare which 

 they possess ; some fishes, e.g., sharks, have a 

 nictitating membrane. — /. MacN aught Campbell, 

 Kelvingrove Museum, Glasgow ; May, 1894. 



Rainfall at Greenock.- — Quantity during the 

 month of February, 1894, 14^07 inches ; number of 

 dry days, 2 ; greatest rainfall in one day, 251 

 (the 6th). February was the wettest month since 

 December, 1852, when 17-06 inches fell, the fall 

 that month being the heaviest of which there is 

 any record in the Water Trust offices. During 

 the past three months the total rainfall over 

 Greenock amounts to 34'34 inches — viz., 9-38 

 inches in December, io - 8g in January, and 14^7 in 

 February, the total for the three months having 

 only once been exceeded — viz., in November and 

 December, 1852, and January, 1853, when 3825 

 inches were registered. The rainfall (i4'07) inches 

 over Greenock in February represents the enormous 

 quantity of 3,410,568 tons of water. 



The Colouring Matter of Birds' Eggs. — I 

 would like to know the easiest and best method of 

 extracting the colour from birds' eggs shells ? 

 Secondly, how I could examine the colour to find 

 out what its nature is? I also would like to know 

 if there is any way of examining the colour under 

 the microscope after being extracted, and how 

 slides of colour could be best made and easiest ? 

 Could the colour be properly examined in the solid 

 state of the shell, if finely powdered, under the 

 microscope, so that its characteristics might be 

 noted ? And, lastly, would any of the methods be 

 likely to be efficient in examining the colouring 

 matter of other kinds of bodies of the same 

 nature, i.e., with calcareous matter in them ? — 

 J. H. Barbour, Queen's College, Belfast ; May 6th, 

 1894. 



The "Squeaking" of Snails. — I had heard 

 of snails emitting a noise, which apparently 

 betokens pain, but I had not hitherto actually 

 heard the sound myself. When a day or two ago 

 I was planting some roots in my garden, I came 

 across the first snail I have seen there this year. 

 I dropped it into an aquarium that was near at 

 hand, and in ten minutes, on looking at it, I found 



it had crawled up the side out of the water, and 

 was standing on the edge with horns extended. I 

 did not wish it to escape, so took it by the shell to 

 pull it away. It immediately gave that shrill little 

 "squeak" which has been noticed, and which 

 seems to resemble the whistle of a locomotive in the 

 far distance. This " squeak " it emitted but once. 

 But it was followed by a series of noises which in 

 tone appeared to be midway between a hum and a 

 low whistle. The cause of the latter sound was the 

 air escaping from inside the shell, between it and 

 the foot, as was shown by the change which it soon 

 made to a hissing noise, caused by the bubbles 

 which followed. It may, of course, have taken 

 some water in during its immersion in its unwonted 

 bath, and this would account for the bubbles. 

 The " squeak " seemed to proceed from near the 

 operculum. — Edward A. Martin, Ravenswood, Carew 

 Road, Thornton Heath. 



Plant Colouration. — With reference to Mr. 

 Alder's note (ante, page 33) on this subject, it may 

 be remarked that the reason why so little notice 

 has been taken of the colours of the other parts of 

 plants than the flowers is that the scientific examina- 

 tion of these parts is much more difficult than that 

 of the corolla. Everybody has noticed the crimson- 

 edged leaves of the wild rose, or the magenta- 

 tinted under- sides of the honeysuckle leaves and 

 others. The red colouring matter of these organs 

 is absolutely identical with that of the flowers of 

 the same species. Not seldom, indeed, dissolved 

 pigments can be detected in the leaves, and yet 

 there are apparently little or none in the flowers, 

 as in the beech, wild cherry, nettle, etc. All this 

 is quite possible, considering that the colour-pro- 

 ducing substance (starch and its derivative, tannin) 

 is found primarily in the leaves, and thence proceeds 

 by way of the petiole, stem and peduncle to the 

 bracts, sepals and petals, or fruits. If any of 

 these conducting tissues offer anywhere in its 

 course a suitable condensating structure, the bright 

 pigment is produced ere it reaches the corolla. In 

 the sycamore, for instance, the bright crimson 

 appears in the petioles and never reaches the 

 peduncles or flowers, and hardly ever the seed- 

 cases. Moreover, everybody who has chemically 

 analysed the leaves of birch, ash, beech, elm or 

 horse-chestnut, is aware that they contain a 

 brilliant yellow dye. Most, probably all, leaves 

 carry a small quantity of carotin, which is identical 

 with the colouring matter of the carrot, the yellow 

 or orange pollens, the orange or brick-red petals 

 and fruits. With regard to the relations of sun- 

 light with the flower colours, the following quota- 

 tions express the state of science on the subject : " 

 " The development of colours in flowers is inde- 

 pendent of the local action of light, and the 

 colouring matters are elaborated exclusively at the 

 expense of the substances found in the leaves 

 under the influence of light." (M. J. Sachs.) — 

 " The development of the soluble colouring matter 

 of flowers depends entirely upon the nutritive 

 matters stored up or on the assimilation by 

 chlorophyll ; in the case of xanthin there is a real 

 dependence between it and the direct light of the 

 sun." (Flahault.) — "The variation in the brilliancy 

 of the corollas has for a cause the variation in the 

 quantity of radiant heat received, which again is 

 proportional to the duration of the light." 

 (Bonnier.) The latter observer recognising that 

 the quantity of leaf chlorophyll increases with the 

 quantity of light received. — (Dr.) P. Q. Keegan, 

 Patterdale, near Penrith. 



