370 HEALTH AND DISEASE 



planation of the origin of seedy toe will suffice which does not embrace 

 and answer this objection. 



In this connection we are of opinion that the foundation of seedy toe 

 is sometimes, if not always, laid by an injury to the coronet, provoking 

 the secretion of a loose and defective horn, and that the seedy or disin- 

 tegrated condition in which it is found does not follow until this part 

 of the crust has grown down to the ground and the degraded horn has 

 become exposed to dirt and moisture. Under the influence of the latter 

 it breaks up into the small seed-like particles from which its name has 

 been derived. 



In 1884 Professor Axe called attention to a nematode worm which 

 he had discovered while microscopically examining the horny debris from 

 a diseased hoof. In reporting the case in the Veterinarian he speaks 

 of finding " thousands of minute, elongated parasites, with their ova, 

 larvae, and structural remains ". The late Professor Cobbold recognized 

 the possible importance of the find, and from his knowledge of the 

 structure and the habits of kindred parasites he had no hesitation in 

 assuring Professor Axe " of their capability to permeate and break down 

 the structure of the hoof in the manner observed in seedy toe". How 

 they are enabled to accomplish this feat of destruction he explained by 

 referring to "a formidable boring-tooth or spike with which they are 

 armed at their oral extremity". 



Professor Axe points out that these parasites are not always to be 

 detected in seedy feet; but it seems quite clear, from the numbers in which 

 they existed in the specimen referred to, that they had found an " agree- 

 able nidus for their growth, development, and propagation ", and by 

 their presence and peculiar armature must contribute in no small measure 

 to the extension of the disease whenever they gain an entrance to the 

 hoof, which Professor Axe points out they may do in an ordinary way 

 through cracks and old nail holes. 



Dr. Cobbold provisionally named the parasite Pelodera Axei and 

 described it as follows: 



"Mouth with broad vestibule and horny style; oesophagus long, with 

 a large round bulb below, armed with dental plates; tail in both sexes 

 long, subulate, very finely pointed; male with two short, nearly equal 

 spicules, no bursa; female viviparous. 



" Habitat. Hoof of the horse (Equus caballus). 



" Measurements. Males ^ f an mcn l n g> females -j inch; breadth 

 of the male -^Q inch, and of the female -^Q inch; length of longer spicule 

 Q^Q inch, of the boring tooth T ^Q mcn > length of the larvae from -^Q to 

 -Q inch; ovum, with coiled embryo, ^Q inch by ^^Q inch; reproductive 



