86 



THE A.MRR[("AN MOXTFTLY 



MnvrU 



result in nuiininals, slnnvii in hlood corpuscles as well as 

 el sew here. 



MrscLK. — The suliji'cl ol" strijicij iniisele hats been inr.cli 

 worked on. but some of the minor poiut.s are the ones of 

 most significance in this jiresent discussion. It is well 

 known tiiat in inaniuials the nuclei of the fibres lie just 

 under the sarcolemma or limiting membrane of the fibre. 

 In the fro^' they lie scattered throuL:;h tlie sarcons sub- 

 stance. Tlie size and shai)e of fibre, number, shai)e and 

 size of nuclei and also the structure of the sarcons sub- 

 stance as apparent from longisections and transections 

 are of significance. The following animals were used: 

 lamprey, amia, frog, amblystoma, cryptobrauchus, uectu- 

 rus, snake, turtle, pigeon, and cat. The results are 

 shown in the following talde. 



Warm blooded and cold blooded animals are sharply 

 cut away from each other with one exception the dijjnoan 

 Protopterus, in which, strange to say, the nuclei are at 

 the edge as in l)ir<ls and mammals. On the whole there 

 is about the same number of nuclei, with one exception 

 to be discussed later. The terms coarse and fine are used 

 to describe the appearance of the fibres in transection. 

 This diflcrencc in diaracter is pr(d>ably due to the vary- 

 ing size of the ct)nstituent fibrils in diflerent animals. 

 If they are large, a coarse effect results; if small, a fine 

 effect. The same fact explains the difference in length- 



