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comparatively shorter ; and that they become corrugated at the tem- 

 perature of 156 of Fahrenheit, when their tendinous and ligamentous 

 attachments are dissolved, and their serous juices coagulated. He 

 then proceeds to give a very minute description of the situation and 

 arrangement of the various series which form what are called the 

 lateral muscles of the body. The nerves belonging to these muscles 

 are also described ; and mention is made of loose transparent vesicles 

 about the size of a millet-seed, containing a white substance like 

 carbonate of lime, which vesicles are found within the sheath of the 

 nerves, at the point of their junctions. 



The rate at which fishes move through so dense a medium as water, 

 is, our author says, very remarkable ; and although this may be partly 

 accounted for by the large proportion of muscles, and their advanta- 

 geous application, yet the power would be inadequate to the effect 

 if it were not suddenly exerted : this appears from the slow progress 

 of eels, and such other fishes as, from their length and flexibility, 

 are incapable of giving a sudden lateral stroke. 



But the quickness and force of action in the muscles of fishes is 

 counterpoised by the short duration of their power. Those accus- 

 tomed to the diversion of angling, know how soon the strength of 

 fishes is exhausted ; for if the hooked fish is kept in constant action, 

 it soon loses the ability to preserve its balance, and turns upon its 

 side. This, Mr. Carlisle says, has been vulgarly attributed to drown- 

 ing, in consequence of the mouth being closed upon the hook ; but 

 the same effects, he says, take place when the hook is fastened to 

 the side or the tail ; and he thinks that this prostration of strength 

 may depend partly on fear, and partly on interrupted respiration ; 

 since fishes, when swimming rapidly, keep the membranes branchio- 

 stegtc closed, and when nearly exhausted, act violently with their 

 gills. 



The shortness of the muscular fibres, and the multiplied ramifi- 

 cations of the blood-vessels, are probably peculiar adaptations for the 

 purpose of gaining velocity of action, which seems invariably con- 

 nected with a very limited duration of it. Such examples, our author 

 thinks, form an obvious contrast with the muscular structure of slow- 

 moving animals, and with those partial arrangements where unusual 

 continuance of action is concomitant. 



Since Mr. Carlisle's former communications respecting the arteries 

 of slow-moving muscles, another instance has been pointed out to 

 him by Mr. Macartney, in the muscles of the feet and toes of birds, 

 which seems to be an adaptation for the alternate rest of their limbs 

 while sleeping. 



The muscles of the human body which perform the most rapid 

 actions, have their fibres subdivided by transverse tendons, or are 

 arranged in a penniform direction. The semi-tendinosus and semi- 

 membranosus of the thigh are thus constructed, and the recti abdo- 

 minis are divided into short masses by transverse tendons. All these 

 muscles cooperate in the action of leaping. 



These observations, the author thinks, tend to explain that diversity 



