160 Trlcldnce qnraUs. 



line of descent appears to have been direct, and the remains now known 

 supply every important intermediate form. It is, of course, impossible 

 to say with certainty through which of the three-toed genera of the Plio- 

 cene that lived together the succession came. It is not impossible that 

 the later species which appear generically identical, are the descendants 

 of more distinct Pliocene types, as the persistent tendency in all the 

 earlier forms was in the same direction. Considering the remarkable 

 development of the group throughout the entire Tertiary period, and 

 its existence even later, it seems very straiige that none of the species 

 should have survived, and that we are indelited for our present horse 

 to the old world. 



Triclihice spiralis: 



The recent excitement in this vicinity about the Trichince spiralis, 

 and especially at Aurora, Indiana, where several persons died from 

 eating diseased jiork, renders any information upon this subject ex- 

 tremely interesting, even though it may not be exactly new. 



In volume ix., page 205, of the Journal of the Linnean Society, Avill 

 be found the experiments with Trichince spiralis, by Cobbold. He gave 

 human flesh containing Trichince to several dogs, a guinea pig, and a 

 hedge hog, all of which died in a few days, and their muscles were 

 found to contain living Trichina'. A piece of the hedge hog was fed to 

 a cat, and another piece to a dog, both* of which died within a few 

 days, presenting the same result. Several feedings of this flesh were 

 administered to a pig, which was kept ten months and then destroyed. 

 It was estimated to contain 16,000,000 living Trichince. inclosed within 

 perfectly formed capsules, none of which latter exhibited any traces of 

 calcareous deposition. A piece of the human flesh was given to a dog, 

 and in sixty-nine hours afterward the dog \\ as killed, and sexually ma- 

 ture living Trichince were found developed in its flesh. The parasites 

 were found in the tongue of a trichinized German subject, at the hos- 

 pital, so closely agglomerated that the point of a needle could not be 

 thrust between the capsules. If all his flesh had been infested to the 

 same extent, it was estimated that he would have contained one hun- 

 dred million living Trichincv. 



An ounce of the trichinized human muscle flesh was administered to 

 a sheep, which was killed in two and a half months afterward, and no 

 Trichince could be found in it. Two cliickens Avere fed with the same 

 material, and at their death no Trichince Avere observed. A croAV Avas 

 fed on the flesh of a trichinized terrier dog, and in a few months there- 



