90 C. b\ MARSHALL. 



Vertebrata. 



The vertebrate animals examined by Mr. Melland were the 

 Frog and the Rat. These will serve as examples of the Am- 

 phibia and Mammalia. I have examined the muscle of animals 

 taken from the other chief groups, viz. the Cyclostomata, 

 Elasmobranchia, Teleostea, Reptilia, and Aves, taking 

 as representatives of these groups respectively : Myxine, Scyl- 

 lium, Gastrosteus, Testudo, and Turdus. 



Muscle taken from each of these animals was treated with 

 the usual gold method, and in each case a network was found 

 identical with that described by Melland. On comparing 

 these networks with one another and with those described 

 above in the striped muscle of the several invertebrate animals, 

 they are found to agree in all respects. 



With regard to Amphioxus, I have not had the opportunity 

 of examining fresh specimens. The muscle has, however, been 

 described as striped, 1 and (from analogy) I see no reason to 

 think that the striation is due to any other cause than a 

 network. In the Ascidian, I have examined the muscular 

 bands of Salpa and find striped muscle present. 



Cardiac Muscle. 



The heart muscle has long been described as faintly striped 

 transversely, but whether this striation is due to the same cause 

 as that to which ordinary striped muscle owes its striation, has 

 not been determined with certainty. 



In order to investigate this point, I made gold preparations 

 of muscle taken from the Rat's heart. The cells are seen to 

 contain a network similar to that of ordinary striped muscle. 

 The network is more delicate and with much smaller meshes 

 than the network in the body muscle of the same animal, and 

 is therefore more difficult to demonstrate by the gold method 

 (fig. 9). I have also prepared muscle from the heart of the 



1 Grenacber, ' Zeit. fur wiss. Zool.,' p. 577. 



