CARNIVOBA 303 



with which must also be placed A. leptoptera of the lion and 

 other felines. The lateral appendages noiT only vary in breadth 

 in these three forms, but also in the specimens obtained from 

 each host. I have encountered examples in a dog, which 

 measured more than six inches in length. The worm is excessively 

 common in England, occurring in probably not less than 75 

 per cent., whilst in Denmark it occurs in about 24 per cent. 

 According to Krabbe it is rare in Iceland. Its presence is at 

 all times more or less injurious to the bearer, being a frequent 

 cause of sickness, colic, convulsive fits, and paralysis. Occa- 

 sionally the worms prove fatal to dogs by wandering into the 

 trachea. At the Eoyal Veterinary College, in 1864, a litter of 

 six puppies, of only three weeks growth, died rather suddenly 

 in consequence of the presence of these worms in the stomach 

 and small intestines. So far back as. the year 1684 Redi de- 

 scribed round worms from the walls of the oesophagus of a dog. 

 These were afterwards noticed by various observers in tumours 

 of the mucous membrane of the stomach. Owing to their red 

 color, derived from the ingested blood of the host, the species 

 was named Spiroptera sanguinolenta. In 1867 I suggested 

 that the minute Filariae found by Grube and Delafond in the 

 blood of dogs would probably turn out to be referable to this 

 species. The researches of Lewis have proved that this suppo- 

 sition was correct. To be sure, other nematoid hsematozoa, of 

 microscopic dimensions, occur in the dog, but those described 

 by Grube and Delafond may be referred to Spiroptera. 

 These authors estimated their number in the canine host 

 to vary from 11,000 to upwards of 200,000. In one instance 

 Messrs Grube and Delafond found six worms lodged in a clot 

 occupying the right ventricle of the heart. Four were females 

 and two males. Although they were described as representing 

 an altogether new species, which they termed Filaria papillosa 

 hcematica canis domestici, I think there can be little doubt that 

 they were examples of Spiroptera sanguinolenta not fully grown. 

 The writings of Lewis abound with interesting details respect- 

 ing the structure and development of this worm, and as much 

 may be said of the writings of Manson and Welch concerning 

 the cruel threadworm (Filaria immitis, Leidy) occupying the 

 right cavities of the heart. I was first made acquainted with 

 this entozoon in 1853, by examining specimens in the possession 

 of Prof. Hughes Bennett of Edinburgh ; at which time also I 

 was put in possession of a valuable MS. (since lost) describing 



