18 THE AMERICAN MONTHLY [Jan. 



and incta-nepliros; in some cases tliey are very consj)icn- 

 ous; tliey unite below the nieta-nepiiros to form a sinjjjle 

 pjiss.'ijre wliicli leads into the bladder on each side. In 

 the higher verlebrales the kidney is a compact organ and 

 the ducts coming from its various |Kirts all unite to form 

 the single ureter Itelore they leave the boundary of the 

 organ. 



The spcniiaiy in male specimens is a com))act organ on 

 tlie level of the meso-nephros; its ducts pass into the 

 ducts from the meso-nephros and thus reach the exterior 

 through the ureter*; in the female there is a duct ovi duct 

 which lies beside the ureter, and is separate from it, this 

 runs way forward to the neck where it opens by a broad 

 funnel shaped orifice directly into the body cavity; near 

 this opening of the ovi-duct lies a large glandular organ 

 the ovary, the ova when they escape from the ovary find 

 their way into the oviduct at its open end and then collect 

 there to jjroduce the appearance described in the begin- 

 ning of this -paragraph. They finally escape through 

 the cloaca into which the ovi-duct ultimately oj)ens. 



10. The Muscular System. — The skin should Ire re- 

 moved from the body and at least one of the limbs to de- 

 termine the following points; the muscle tibres will show 

 much more distinctly after preservation in alcohol or 

 after boiling. The system as a whole includes: the 

 muscles connected with the viscera itivoluntary viuficles\ 

 and the muscles attaching to the skelton and used ia 

 changing the forn» an<l position of the body, skeletal ?nus- 

 cles. Of these latter we may distinguish those of the 

 head, and those of the (rest of the) body. It is to the lat- 

 ter that the ])re8ent study is mainly confined. Two 

 kinds are reconizable : those of the sj)ine used in pro- 

 ducing the bendings of the back-bone, spinal muscles; and 



*Besi<lea the sper . ary there it nt-rerally i" the miilfs a orpm oji each 

 side resciubliug is batcoiuposed tuuinly oi" lat called the corpus adiposuiu. 



