244 THE AMERICAN MONTHLY [Ang. 



BotDmamfs Disks. — Macerate a small muscle in dilute 

 acetic acid (1 c.c. acetic acid to 400 grms. water.) and 

 dissociate on a slide by needles. . . . 



Vessels of Striated Muscles. — Inject an animal with tlie 

 Prussian blue gelatine to be described hereafter ; choose 

 a muscle with parallel fibres, and make longitudinal and 

 transverse sections after fixing in bichromate, hardening 

 in alcohol, embedding in gum ; mount in balsam. In- 

 stead of sectioning we can take a thin and transparent 

 abdominal muscle of a frog, spread it on a slide and 

 mount it flat in balsam. 



Nerve Endings iu Muscle. — . . . .From a frog just kill- 

 ed take a muscle and fasten it to cork by sharp quills. 

 For five minutes place it in lemon juice freshly expressed 

 and filtered through flannel ; wash the muscle rapidly 

 and put it in a 1 per cent solution of chloride of gold 

 for 20 minutes. Wash again for one second, reduce in 

 the dark in I formic acid (water, 4; formic acid 1). The 

 next day, the reduction of the gold completed, mount in 

 formic acid glycerine. . . . 



To study the Motor Plates of the Lizard. — Mix 4 parts 

 of chloride of gold with one part of formic acid. Boil 

 and cool. Place a bit of muscle in 2 c. c. of pure gold 

 chloride and add drop by drop a few c. c. of the boiled 

 gold and acid. Reduce in the i acid. Dissociate on a 



slide ; mount in formic acid glycerine 



UNSTRIATED MUSCULAR TISSUE. 



For this study nothing is better than a frog's bladder. 

 Kill a frog and put a strong ligature around the cloacal 

 orifice. Open the abdomen on the lower surface and cut 

 the rectum at the upper end. In the rectum insert a 

 syringe charged with the 1-3 alcohol, or with ammonia 

 bichromate, and gently depress the piston. The fluid 

 enters the cloaca whore the ligature retains and forces 

 it to pass into and to distend the bladder. . . .Place a 

 ligature beyond the syringe, remove iu one piece the 



