64 



•aquatic JLite 



Aquatic Safe 



A monthly magazine devoted to the study, 

 care and breeding of native, tropical, gold 

 and fancy fishes, other animals and plants 

 in the household aquarium. 



W. A. POYSER Editor 



JOSEPH E. BAUSMAN .... Publisher 

 542 E. Girard Avenue, Philadelphia 



Entered as second-class matter, September 

 2, 1915, at the Post Office, Philadelphia, Pa., 

 under Act of March 3, 1879. 



Yearly Subscription $1.00 



Foreign Subscriptions 1-35 



Single Copy 10 cents 



Payments may be made by express money 

 order, draft, post office order or registered 

 letter. Foreign remittances should be by 

 international money order. 



Advertising rates made known on application. 



"Aquatic Life" is the only magazine in 

 America devoted exclusively to aquatic life, 

 and its value as an advertising med'um in 

 this field of nature study is unequaled. 



Copyright 1917 by Joseph E. Bausman 



Vol. II 



January, 1917 



No. 5 



Among the cells of the outer layer, both 

 on the body and the tentacles, are numer- 

 ous stinging or thread cells ; these resem- 

 ble somewhat those of Paramecium, but 

 are of a more highly organized nature. 

 The threads are discharged whenever 

 the animal is irritated, and are also used 

 for obtaining food, for when a cyclops 

 or other small animal comes in contact 

 with the Hydra it is paralyzed by the 

 discharge of one of these stinging cells, 

 and is then drawn into the mouth by 

 the tentacles. The Hydra attaches itself 

 to an' object by secreting a sticky sub- 

 stance from the cells of its base. It 

 rarely moves about, but may do so by 

 holding on with the tentacles and moving 

 the base. 



It multiplies either by budding, which 

 is simply a process of a new hydra 



growing out of the side of the old one, 

 or by the production and fertilization of 

 eggs, the body containing both an ovary 

 and a spermary. 



The planarian worm is another form 

 of life generally found in old standing 

 water, especially that into which plants 

 have been introduced from outside 

 sources. It resembles a leech in gen- 

 eral appearance, but is very much 

 smaller, rarely exceeding an eighth of 



Hydra 



1. Lengthwise section of body, showing: 

 A, mouth; B, tentacle; C, reproductive bud; 

 D, spermary; E, ovary; F, body cavity; G, 

 ectoderm (outer layer of cells) ; H, entoderm 

 (inner layer of cells); J, stinging cell. 2. 

 Section across body. 3. Mature Hydra con- 

 tracted. 4. Same extended. (Figures 1 and 

 2 greatly magnified; 3 and 4 slightly en- 

 larged). 



an inch in length. It is soft and jelly- 

 like, of a grayish color, and changes its 

 shape very readily. The most striking 

 characteristic is that it is extremely 

 cross-eyed, presenting a very queer ap- 

 pearance when viewed under the micro- 

 scope. It is sometimes found attached 

 to fishes and the tenacity with which it 

 holds on is surprising. 



