424 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



the most part lost, owing, as I thiuk, to the circumstance that the water 

 was allowed to flow too rapidly and violently through the hatching jar. 



The behavior of the hatching jar was most admirable, but would have 

 been still better had there been a larger quantity of eggs put into the 

 apparatus. The most meritorious feature of the ai^paratus is the almost 

 entire non-development of the saprolegnious fungus, which causes so 

 great a mortality in some other forms of hatching contrivances in which 

 all of the ova are not in continual movement. The very gradual, gentle, 

 and continual rolling movement of the ova upon each other in the jar 

 apparently prevents the spores of the fungus from adhering. The 

 cleanliness of the apparatus is also to be commended, whereby the use 

 of skim nets for cleaning is dispensed with, while the material of which 

 it is made — glass — enables one to watch the progress of development 

 very satisfactorily from the outside of the jar with a hand-glass or pocket 

 lens of moderate power. 



On the seventeenth day of the experiment the hatched embryos were 

 in the condition of those normally developed at 70° to 75^ Fahr., the 

 yelk being ovoidal, clear, and plump. At the rate at which the develop- 

 ment progressed, it would take live times as long to absorb the bulk of 

 the yelk of an embryo at a temperature of 53^.75 Fahr. as at 75° Fahr., 

 or about 25 days. This period, added to the prolonged time of incuba- 

 tion at 530.75 Fahr., would cover a space of forty days, or more than 

 twice the time required to carry embryo shad to the farthest confines of 

 Europe. The probability therefore is, that we have exceeded the low- 

 est temperature practically required for this purpose; 55° Fahr. being 

 a much more favorable and less dangerous temperature than that pre- 

 vailing during the successful experiment of which we have just given a 

 detailed account. 



Washington, A2}ril 26, 1882. 



GKO^VTH A!\I> S1PAWIV5IVCJ OF GEHMAIV CARP IN AliABAMA. 



By A. G. BAK]\ES. 



[Letter to Prof. S. F. Baird.] 



It will jierhaps interest you to have a report from my German cari). 

 Those received January 12, 1881, are now 20 inches in length. The first 

 iudications noticed of their breeding were in March last (the nineteenth 

 day). A lot of eggs, found attached to the grass, was taken and place 

 in a tub, and the young were seen on the seventh day afterwards — 

 the weather cool and wet. Again, on 2d instant I saw them depositing 

 their eggs. A lot of these eggs placed in a tub hatched out on the 

 fourth day — the weather warm and pleasant — the water during the 

 day indicating about 70^. Those hatched 2Gth March are now 1^ inches 

 in length. 



