868 



ZOOLOGY. 



rarely exceeds that of the water iu which the fish swims by so much as 

 a degree, " so that it may be quite safely taken as an index to the latter 

 temperature when there is no deep-sea thermometer at hand " 



The experiments of Dr. Kidder were made not only in the rectum and 

 stomach, but in various parts of the muscular tissues, the large venous 

 trunks, the cavity of the thorax after opening the heart, the interior of 

 the hear , and branchial artery, and theyouug fish in theovary. Althou^^h 

 Dr. Kidder admits the results to be only tentative, he considers thlt 

 enough has been ascertained to show that fishes do develop animal heat 

 by their own vital processes in the same manner, but in a less deo-ree 

 as do the higher vertebrate animals, and that they will be found to mani- 

 test a temperature much above the water in which they swim The 

 temperature, however, varies according to the organization ami the 

 species. Thus the dog-fish (Squalus acantMas), in common with other 

 sharks," possessing a far more perfect digestive and circulatory sys- 

 tem than the cod, shows a much greater excess of blood tempera- 

 ture above that of the surroun<ling water; and cod taken at the Tpth 

 of lo fathoms in water at 52o p., show a less excess than others taken 

 m 25 fa homs at 41o F., but a greater excess than blue-fish (Pol« 

 tomus saltatn. (Linn.) Gill) taken at the surfiice, at G9o and TOo^wMch 

 IS presumably nearer the normal temperature of the last-named fish " 

 bv DrKiTr'' ^'^'!'i ""l'^.^«^^«°^ 1<5 species, were experimented upon 



the^ol'ln ' ' ''''"^ '''' '^""^™ ^^"^^ ^"^i^^^^'^^t observations, 



the following is a summary of the results : ' 



Fish. 



Cod 



Haddock 



Pollock... 



Hake 



Blueiisli 



Do ''.'.'.[' 



"Tinker" mackerel 

 "Tinker,^' S.Dekayi...'. 



Sculpiu 



Sea-raven 



Eelpout " ] ] 



Flounder " 



Dogtish ....'. 



Dogtish, young in ovary 



Degrees, 

 39-42 



42 

 42 

 73.2 



70.5 



65 



60 



60 



70.6 



Temperature Temperature 



of rectum of circulation 



above water, above water. 



Degrees. Degrees. 



42 

 42 

 42 



0.98 



1.3 



2.4 



2.4 



0.25 



0. 5 



4.1 



Eemarks. 



0.8 



4.4 



4.63 

 5.3 

 4.5 

 9.8 



*1.55 



tl.7 

 5. 25 

 2.3 

 3.2 

 4.4 

 6 

 3 



12 



20.6 



Spawning. 



"Thorax." 



Do. 



Do. 

 Stomach. 



' Below. 



t Above. 



THE OVARIES OF TELEOST FISHES. 



nf^r ^' f'""^^" ^'!'' iyestigated the anatomy and histology of the organs 



iJo^k^nLch;!" ''"*''°" '" ^"'''"" ""^' '^^^*«^«°^- •I- Gescm^^ttso^^s^^^, 



