248 



ANATOMY. 



ends of the muscles, by which they are attached to the parts to be 

 moved : the muscle itself is the contractile fleshy portion lying between 

 these tendons. If the tendon be wanting, the entire generally very 

 broad end of the muscle is affixed to the horny skeleton, and such 

 muscles appear applied more to the strengthening of all the parts than 

 to the motion of individual ones. 



The tendons vary much in shape according to the structure of the 

 muscle, but they always consist of a horny mass, distinguished from 

 that of the skeleton by its wanting the epidermis, and the coloured 

 layer of the mucous tunic, and therefore Straus considers them as an 

 elongation of the internal layer of the horny skeleton, to which the 

 epidermis cannot assist, as it lies externally, and this view appears 

 to be correct. The horny tendons, consequently, cannot participate 

 in the external colour of the exterior integument, but they are, like its 

 internal layer, of one uniform black or brown hue, so that they are easily 

 distinguished from the flesh of the muscle. In form they are longer or 

 shorter bones, which, at the side turned to the muscle, gradually 

 distend into a flat surface, to which the muscle is attached. The form 

 of these surfaces varies according to what is required by the muscle, for 

 it is broad and plate-shaped for short thick ones, and for long thin ones 

 we find it also long and resembling a scale. 



The muscle itself is a union of delicate white, or yellow and red 

 parallel fibres, which frequently, particularly if the insect has been 

 preserved in spirits of wine, are readily separated from each other. 

 If these fibres be examined under the microscope, we distinguish 

 partitions at short distances, which appear to separate it in equal parts; 

 but upon a careful examination, we find that the fibre consists of small 

 lamina? lying one upon the other, and which at one spot are de- 

 pressed into an angle, and are thereby attached to each other, which 

 consolidates their union. This discovery, for which we are indebted 

 to the careful Straus*, is the more important, as thereby we detect a 

 uniformity of structure of the animal organs in their most minute parts, 

 as the fibres of the nerves likewise consist of consecutive globules. In 

 the muscular fibres these globules have become plates from their firmer 

 connexion together, and their consequent mutual pressure. Straus 

 found this union in all the muscles, but in the larger ones the indi- 

 vidual fibres first formed bundles, whereas, in the smaller ones, they lie 



* Consid. General, p. 143. 



