HARDWICKE'S SCIENCE-GOSSIP. 



273 



OUR SCIENTIFIC DIRECTORY. 



[The Editor will be obliged, if, for the benefit of his numerous 

 readers, secretaries of scientific societies will send notices like 

 xhe following, also place and time of meeting.] 



J~yAST London Natural ffistoiy and Microscopical 

 JH^ Institute: President, W. Smart, M.P.S., 

 M.Q.M.C. ; Hon. Secretary, A. Dean, M.Q.M.C, 

 57 Southborough Road, South Hackney, N. 



Hackney Photographic Society : President, Dr. 

 Roland Smith ; Hon. Secretary, W. F. Jones, 

 12 King Edward Road, Hackney, N.E. 



THE COLOURING OF THE EGGS OF 

 "WILD BIRDS AT THE SMALLER END. 



IN the present day when the microscope and the 

 scalpel are revealing so much, they may both 

 assist in elucidating the following zoological fact, i.e., 

 that the eggs of the Falconidas are so much more 

 frequently coloured at or around the smaller end than 

 those of any other bird. 



I regret I am unable to state anything positively as 

 to the eggs of the larger Falconid3e,but the specimens 

 I have show a very strong tendency in that direction. 



Taking the eggs of the sparrow-hawk as typical 

 eggs of this family, I find that at least 40 ^^ show the 

 peculiarity to which I refer. Some of these eggs are 

 most beautifully blotched with two or three shades of 

 brown, quite covering the smaller end of the shell, 

 leaving the remaining portion almost spotless. 



In a series of clutches of the rook and the magpie, 

 10 % of the eggs show the smaller end marking. In 

 ten clutches and some odd specimen of the eggs of 

 the red-backed shrike it only occurs once. I mention 

 this, as I see Mr. H. Seebohm gives a beautiful 

 illustration of one of these eggs in his last work. 



The eggs of the tree-sparrow {Passer viontanus), 

 which are very erratic both in colour and size, show 

 the small end marking to at least 10"^. In one 

 clutch of five eggs I see three examples, but curious 

 to relate that in icx)0 specimens of the eggs of the 

 common sparrow [Passer domesticus), there is not a 

 single example. The corn bunting (E. miliaria) 

 which lays a large egg does not show it, but the 

 yellow bunting {E. citrinella) does, in having a zone 

 of lines around the smaller end, but not blotched. 



This phenomenon may have been thoroughly ex- 

 plained, if so, I plead great ignorance, but as I have 

 not at present met with it in print, I beg to offer the 

 following remarks, which may perhaps "be laughed to 

 scorn" by physiologists. 



I think it may fairly be taken for granted that the 

 Falconidse and the Corvidae lay eggs which are small 

 in proportion to the relative weight and size of their 

 bodies ; then, if their internal organs are formed in 

 relative proportion to their size, the oviduct or cloaca 

 — I do not know which term is the most correct — must 



be sufficiently large to allow the egg before it receives 

 its hard shell to turn and give an unnatural presenta- 

 tion which would bring the smaller end in contact 

 with the colouring glands. There can be but little 

 doubt that all eggs, when first formed in the oviduct, 

 have the foUiculus aeris in the larger end and pointing 

 to the vent ; consequently, to cause unnatural presenta- 

 tion the egg must turn when enveloped only in the 

 albuminous membrane. 



Now, turning to the eggs of the guillemot, gulls, 

 terns, curlew, oyster-catcher, snipe, &c., which lay very 

 large eggs, this phenomenon does not appear, owing, 

 I believe, to the eggs being so large in proportion to 

 the birds, they are held — all through their develop- 

 ment — more firmly in the oviduct. 



A great deal more may be said on this subject, but 



I shall be making this paper too long ; however, I 



must state that the figures I have given are taken from 



the clutches of eggs in my own collection, of all of 



which I know the history. Those who have a series 



of reliable clutches of the eggs of the birds mentioned 



above can either confirm or refute what I have said, 



but no reliable information can be obtained from a 



lot of odd specimens. 



Joseph P. Nunn. 



NOTES ON ECONOMIC BOTANY. 

 By J. T. Riches. 



C~*RUCIFERA^ (MUSTARD). — This well- 

 • known condiment and rustic medicine is the 

 produce of two species of Sinapis, a genus belonging 

 to the cabbage family, possessing that characteristic 

 pungency to a great extent. Both species are natives 

 of this 'country {S. alba, Linn.), have nearly smooth 

 leaves, pinnated, silique valves five-nerved with a 

 ord-swshaped apex, seeds yellow. The seed leaves — 

 cotyledons— of this species are eaten with garden 

 cress {Lepiditim sativum), as a salad. The seeds 

 sometimes are taken whole as stomachics and laxa- 

 tives, and crushed between rollers, sifted two or three 

 times, constitute "flour of mustard;" from the 

 residue a fixed oil is obtained by pressme. The 

 seeds of black mus\ard are also mixed with them, 

 and probably are very often used in the greatest 

 proportion. 



S. nigra, Linn., is a native of, and is largely 

 cultivated in this country, about Yorkshire and 

 Durham. The plant is covered with trispid hairs. 

 Leaves lyrate, silique short, bluntly quadrangular, 

 seeds reddish-brown, smaller than the seeds of 

 S. alba. The chemical constitution of mustard is 

 very complex ; among the various ana numerous 

 ingredients is a peculiar acid called myronic acid, 

 containing a small proportion of sulphur, and which, 

 when mixed with water and a peculiar substance also 

 present called "mysorine," yields volatile oil of 

 mustard ; which, it is said, has not separate existence 



