HARDWICKE'S SCIENCE-GOSSIP. 



55 



material, and secondly, such crowded bottles very 

 quickly go wrong. 



On arriving home, I turn out the contents of the 

 bottles into three or four small window aquaria having 

 flat and parallel sides. I would here strongly recom- 

 mend the use of these window aquaria for keeping 

 and examining pond-life ; they save a great deal of 

 time and trouble, and I find them quite indispensable. 

 Mr. Watson, glass cutter and aquarium maker, of 

 161, Great Portland Street, London, makes them ; 

 6 in. long by 5! in. high, and 8 in. by 6 in., are two 

 convenient sizes. 



A number of objects escape notice in the ordinary 

 round aquaria and bottles, but in these flat aquaria, 

 which are not more than 1 or ij in. thick, every part 

 can be seen and examined with the pocket-lens with 

 great ease. On placing the aquarium in front of a 

 window or lamp the free swimming forms will collect 

 on the side nearest the light, and any one of them, 

 even the minutest, can be picked up with a dipping- 

 tube, provided with an indiarubber teat, acting as a 

 syphon. 



I need hardly mention the necessity of examining 

 the objects as soon as possible, and not later than the 

 day after their having been collected, as many 

 organisms soon die in captivity, presumably from 

 want of proper food. The life of Rotifers can be 

 prolonged a little by feeding them twice a day with 

 a green soup, made by crushing some Anacharis, or 

 any other water weed, in a little water in a mortar. 

 That they really eat this, can be seen under the 

 microscope. After several days' captivity Rotifers 

 look very white and hungry, biting at each other and 

 trying to swallow each other's spines ; but when a 

 few drops of the soup are added to the trough, their 

 stomachs very soon assume a more comfortable green 

 appearance, becoming filled with little balls of 

 chlorophyll. 



In conclusion I would recommend microscopists to 

 examine ponds and collect in winter as well as at the 

 other seasons, for in my experience Rotifera and 

 Infusoria are then, even under the ice, as abundant, 

 if not more so, than in the summer months. 



I trust these few remarks will be found useful to 

 the younger collectors ; I have found the methods 

 described most efficient and time-saving, which is an 

 important consideration to most of us who pursue 

 this study as a recreation. 



C. ROUSSELET. 



RUDIMENTS.— A REPLY. 



IN discussing the advisability of retaining Mr. 

 Darwin's use of the word "rudiment," it will 

 perhaps be well to consider first the right application 

 of the term. Either the organ so designated must be 

 in an early stage of a future development, or in an 

 inferior condition, compared with a higher standard. 



Your correspondent Mr. Trevor-Roper attributes 

 the latter sense to Mr. Darwin. 



Now, as the term "rudimentary" can only be 

 used in relation to a recognised standard of per- 

 fection, we are forced into the strange position of 

 seeking for the perfection of our so-called rudi- 

 mentary organs in the lower animals. 



To those who have grasped the theory of develop- 

 ment, this cannot but appear an anomalous pro- 

 ceeding. 



The brain of man, so undeniable in its superiority, 

 has perhaps alone escaped the stigma of being 

 "greatly reduced from a perfect state," and to it 

 is attributed solely the dominating position in which 

 man now finds himself. 



We have been told that our sight, hearing, smell, 

 etc., are in a lower state of development than that of 

 our earlier progenitors severally, and we have ac- 

 cepted the statement with unquestioning reverence. 

 So with teeth, lungs, the down on the body, and 

 indeed, almost every part of the human structure. 



But we must ask if these assertions will bear 

 examination, and whether our senses are inherited 

 " in an enfeebled and rudimentary condition," as Mr. 

 Darwin states of the sense of smell. I am inclined to 

 doubt it, and before deciding hastily which is rudi- 

 mentary and which is perfect, to weigh quality with 

 quantity, to consider the economy of material, to find, 

 if possible, the most comprehensive capacity in the 

 least space. 



And where is it to be found ? Not in the compound 

 eye of the dragon-fly, though it sees " equally well in 

 all directions — before, behind, or laterally," nor yet 

 in the far-sighted eyes of certain birds, that may 

 excel in distance of vision, but in the organ of sight, 

 which, one of our greatest anatomists tells us, 

 " arrives" in man " at its highest perfection." 



Put the dragon-fly or the bird into a gallery of 

 pictures, and it is clear that delicacy of colouring and 

 disposition of light and shade are lost upon them. 

 Even the beauty of a landscape, or a fine sunset, 

 excites no pleasurable recognition of harmonious tints. 



Certainly, according to Mr. Darwin, wonderful 

 changes have been wrought by the preference of the 

 female Polyplectron for the ball and socket ocelli in 

 the plumage of the male bird, but this is a suppo- 

 sition to be weighed ; and even allowing this, no one, 

 I suppose, would venture to compare, for delicacy of 

 perception, the bird's eye with man's. 



And again, with regard to the sense of smell. The 

 bloodhound can track out and discover a runaway 

 slave by the mere smelling of a garment, but has no 

 perception of, or delight in, the varied scents of 

 flowers, though carrion attracts him. The sense of 

 smell is keen, but not refined. 



It is quantity versus quality. How, under these 

 circumstances, can the sense of smell be said to be 

 inherited by us "in an enfeebled and rudimentary 

 condition " ? 



