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T H E 



A Q L A R I U M 



In about ten days all the fungus be- 

 gan to disappear very rapidly, the water 

 cleared beautifully, and I noticed young 

 shoots of Sagittaria beginning to show- 

 up. They increased with surprising ra- 

 pidity — the water did not turn green 

 and conditions seemed eminently satis- 

 factory. Then I introduced fish, which 

 did well from the first. Now, after seven 

 months, in spite of poor conditions, the 

 plants are thriving and multiplying in 

 my 80 gallon aquarium. Aquarium No. 

 2 gave me exactly similar results, only 

 much slower and with more work, as 

 the plants had to be fed continually. 

 I do not hesitate in recommending the 

 sheep-manure method to anybody who 

 is troubled with a poor growth of plants, 

 provided the aquarium is set up as I 

 have suggested. 



Now, in conclusion, a few words about 

 Daphnia. 



Some time since, I wrote an article 

 for The Aquarium, on the propagation 

 of Daphnia, in which I suggested feeding 

 them on infusoria raised in hay infu- 

 sions. I have recently come to the con- 

 clusion that the very best medium to 

 employ in raising Daphnia in quantities 

 is either Spirogyra, Cladophora or Zyg- 

 nema. Since September 10th, 1912, I 

 have raised, in a twelve gallon aquari- 

 um, sufficient Daphnia to supply one 

 dozen large fish with a liberal feed once 

 a week, and my start consisted of about 

 a quart of Spirogyra and Cladophora. 

 These Algae have been growing and fur- 

 nishing the young and old Daphnia with 

 plenty of food ever since. I see no rea- 

 son why a breeder cannot breed Daphnia 

 enough to raise his young fish on if he 

 uses Spirogyra and a sufficiently large 

 tank, making the start in the fall. 



Of Interest Regarding Gambusia 



By W. S. HILPERT. Chicago, III. 



One of the most interesting studies 

 carried out during the past summer at 

 the Laboratory of the Bureau of Fish- 

 eries at Beaufort, N. C, is that reported 

 by Dr. Albert Kunz, of the University 

 of Iowa, in "Science," vSept. 19th, 1913. 



Dr. Kunz's studies were devoted to 

 the morphology of the reproductive or- 

 gans of Gambusia affinis which abounds 

 in the vicinity of Beaufort, in all the 

 fresh water streams entering the harbor. 

 His eflforts were especially directed to 

 the structure of the apparatus control- 

 ling the modified anal fin in the male 

 Gambusia. "This fin," the report tells 

 us, "functions as an intromittent organ 

 and is controlled by a powerful muscle 

 which has its origin on a boney process 

 projecting ventrally from the fourth to 

 the last abdominal vertebrae and the 

 modified anal spines of the proximal end 

 of the anal fin rays. The third, fourth 

 and fifth rays of the fin are enlarged, 

 greatly elongated and variously curved, 

 bearing short spines on their distal por- 

 tions. The interhemal which articulates 

 with the third ray is enlarged and suf- 

 ficiently elongated to articulate with the 

 two anterior processes, on which the 

 muscle controlling the anal fin has its 

 origin. The fifth ray may be drawn for- 

 ward at one side of the fourth and 

 brought into proximity with the third. 

 In this manner a groove or tube is form- 

 ed through which the milt is transferred 

 from the male to the female." 



"The utility of the study in natural 

 history will be recognized by anyone 

 possessing even rudimentary ideas of 

 the science." — Milne-Edwards, 



