86 C. F. MARSHALL. 



for ten minutes, and left in the formic acid in a warm chamber at 

 40°C. for two hours. 



Insect Larva. — To determine if striped muscle is present in the 

 larval insect as well as in the imago, I made preparations from the 

 larva of the Ermine Moth (Spilosoma lubricepecla). Muscle was taken 

 both from the jaws and from the legs. In both cases the muscle 

 was found to be striped, the network in the muscle of the jaw being 

 especially well developed. 



Arachnida. — Muscle taken from the leg of the Spider and treated 

 with gold showed the network of striped muscle. 



Vertebrata. 



The vertebrate animals examined by Mr. Melland were the Frog 

 and the Eat. These will serve as examples of the Amphibia and 

 Mammalia. I have examined the muscle of animals taken from the 

 other chief groups, viz., the Cyclostomata, Elasmobranchii, Teleostei, 

 Reptilia, and Aves, taking as representatives of these groups respec- 

 tively : Myxine, Scyllium, 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 de- 

 scribed as striped,* 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 of Vertebrates. 



The heart-muscle has long been described as faintly striped trans- 

 versely, 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. 



* Grenadier, "Zeit, f%wiss, Zool.," p. 577, 



