PRACTICAL DIRECTIONS. 433 



mended, mould is almost sure to attack them. Material neglected 

 for a week may thus be ruined. 



If mould is found at any time to be attacking the material, the 

 attacked part should be cleaned and well wrapped in cloths saturated 

 in the formalin- glycerine mixture. If such means are unavailing, the 

 specimen should be immersed in a vessel of one per cent, formalin 

 and preserved for the future in this. Recourse should be had at 

 once also to this method of preservation if the specimen shows signs 

 of decomposition by having a strong odor. 



It seems probable that the attacks of the mould might be 

 prevented by mixing some fungicide with the injecting fluid; experi- 

 ments should be made in this direction. 



There are many advantages in preserving the material if possible 

 without immersing it. All parts retain their color and pliability 

 much more completely, so that the different structures are much 

 more easily distinguishable. The method above described, by the 

 use of formalin and glycerine, is to be recommended when the 

 material is to be worked on every day or so and is not to be kept 

 longer than a few weeks. It is usually not very satisfactory in warm 

 weather, however. If some method can be devised of entirely pre- 

 venting the attacks of the mould, this will be an excellent method of 

 preserving anatomical material. 



The same specimens used for the study of the muscles will serve 

 also for the spinal cord and brain if prepared by one of the methods 

 above described. (For the viscera, blood-vessels, and nerves, other 

 specimens will have to be prepared; for these, directions are given 

 later.) 



Muscles to be Dissected. It will probably usually be impossible 

 in a given course of study to dissect all the muscles of the cat. The 

 instructor will of course select such as seem most advisable to him. 

 The following may perhaps be recommended as a good selection 

 for a fairly extensive course: Muscles of the Fore Limbs (pp. 436 

 439); Muscles of the Neck and the Deep Muscles of the Head (pp. 

 439-441); Muscles of the Wall of the Thorax and of the Abdomen 

 (pp. 441-442); Muscles on the Ventral Side of the Neck (p. 442). 

 If the superficial facial muscles (excluding those of the ear) can be 

 studied from a preparation, this will be a valuable addition to a 

 course (pp. 434-435). 



DISSECTION OF MUSCLES. 



General. In dissecting muscles a prime requisite of successful 

 dissection is to keep the muscles clean. Fat, connective tissue, etc., 

 is to be carefully but thoroughly cleared away from the surface of 

 muscles and from between them. Frequently when it seems impossi- 

 ble to distinguish the structures described, all difficulty will vanish 

 as soon as the dissection is thoroughly cleaned. 



