ZOOLOGICAL SOCIETY BULLETIN 



1553 



been found in plankton — the floating matter of 

 the water — in wet moss, and other small plants 

 of the rivers, swamps and ponds. Low temper- 

 ature is evidently pleasing to the water bears, 

 for, rare at all times, they are still more rarely 

 found in summer than during the cooler 

 months. 



In Illinois they have been observed from Oc- 

 tober to May. The one here pictured was 

 found toward the last of May in a balanced 

 aquarium where she had probably been all win- 

 ter, having taken up her abode for the time 

 being with various other minute animals in the 

 dead egg of a red ramshorn snail. There it was 

 that she cast her skin and left her progeny. 

 The latter's small feet traveled around and 

 across the egg a great many times. An egg 

 1/32 of an inch in diameter was, of course, a 

 little world in itself — a microcosm — to such in- 

 finitesimal creatures. They showed no haste to 

 leave it and seek their fortunes in the deep, ex- 

 pansive lake wherein the egg reposed — in a 

 watch crystal. 



Another specimen, since discovered in Au- 

 gust, was groping among the stems of some 

 stalked protozoans attached to the shell of a 

 Potomac snail. 



Some of the bear animalcules live on land, 

 and on the roofs of houses, others in moist sand. 

 Some live only in temporary pools, others in 

 the seething ocean ; and far removed from civ- 

 ilization, still others dwell high up in the Arc- 

 tic mountains. Some travel about in tiny coats 

 of mail. One species — that which lives in moss 

 — suffers no permanent injury from drying up, 

 surviving terrible heat and drought. It is said 

 that even after years of dessication, a drop of 

 water will bring it to life. Without heart or 

 blood vessels, the fluid in the body which serves 

 as blood need not necessarily be peculiar to this 

 Tardigrade; and perhaps that is the queerest 

 thing about him. When it has dried up, a touch 

 of moisture will replace it and serve quite as 

 well. During drought, therefore, the members 

 of this species remain like invisible particles of 

 dust. A drop of rain, and back to life they 

 come. 



The restlessly active little water bear has his 

 place somewhere in the great scheme of life on 

 earth, self-intent and self-content, and quite un- 

 aware that he has been found out by giants 

 studying zoology, whose infinitely larger brains 

 than his are so severely taxed to discover what 

 manner of beast he is. "Solicit not thy thoughts 

 with matters hid." — Little did Milton know the 

 temptations of the microscope. 



ITEMS OF INTEREST 



By C. H. TOWNSEND 



A New Book on Small Aquaria. — In Gold- 

 fish Varieties and Tropical Aquarium Fishes, 

 Mr. William T. Innes presents a useful guide 

 to aquaria and related subjects. Among the 

 subjects dealt with are the fresh-water aqua- 

 rium, goldfish varieties, hardy native fresh- 

 water fishes, tropical aquaria, marine aquaria, 

 terraria, fish foods, diseases, plants, construc- 

 tion of aquaria, etc. 



The author is equipped jby long experience 

 for his task, and has performed it so well that 

 the book will take an important place among 

 manuals devoted to the subject. 



The following quotations contain the essen- 

 tials of aquarium management: 



"The main causes for failure, in the order of 

 their importance, are overcrowding, overfeed- 

 ing, sudden temperature changes, lack of proper 

 plant life, insufficient lighting." 



As to overcrowding, the rule given is : 



"One inch of fish to one gallon of water — 

 that is, in a ten-gallon aquarium of the usual 

 oblong shape, well planted and in a good light, 

 one could successfully keep ten one-inch, or five 

 two-inch, or two five-inch fish. 



"Fish should never on any account be fed 

 more than will be consumed at once. 



"Do not subject the fishes to any sudden 

 change of temperature, either higher or lower 

 .... A sprinkling pot is excellent for adding 

 water to the aquarium. 



"If oxygenating plants are not used the fishes 

 become restless, come to the surface to breathe 

 air, and may finally die of suffocation unless 

 the water is changed. 



"Select for the aquarium a place close to a 

 window with a good strong light, preferably one 

 where it will get two hours of direct sun a day." 



In conclusion, the author gives a list of very 

 sensible Dont's, which, if well considered by 

 the amateur, ought to carrj'^ him far on the way 

 to success. 



The book is well printed, well illustrated, and 

 its matter is well presented. Undoubtedly it 

 will introduce many to the pleasant art of keep- 

 ing aquaria. 



Larger Ed'hibition J'anks.—The picture of 

 sturgeon and dog shark shows the effect that 

 can be produced in the enlarged exhibition 

 tanks that have been constructed in the Aqua- 

 rium during the past two years. The work of 

 enlarging; tanks will be resumed soon and it is 



