NEMATODA 157 



capsules. Not a few persons still entertain the notion that 

 Trichinae are liable to infest all kinds of warm-blooded, and 

 even also many kinds of cold-blooded animals, such as reptiles 

 and fishes. Certain nematodes found in earth-worms have been 

 described as TrichinaB ; and consquently, pigs and hedgehogs 

 were said to become trichinous through eating these annelids. 

 The minute flesh-worms described by Bowman from the muscle 

 of the eel are not true TrichinaB, any more than the somewhat 

 similar parasites which Eberth found to infest the muscles of 

 the frog. The same may also be said of Dr Salisbury's 

 urinary Trichinae, which are the larvae of Filaria Bancrofti. 



Deducting the seven birds, and also six other animals where 

 no examination after death was possible, I ascertained the 

 result of my worm-feedings in sixteen instances. Nine of the 

 experiments were entirely successful, the infected animals 

 comprising four dogs, two cats, one pig, one guinea-pig, and a 

 hedgehog. 



Carnivorous mammals, especially those subsisting on a 

 mixed diet, are the most liable to entertain Trichinae, but it is 

 quite possible to rear them in herbivora. Thus, Pagenstecher 

 and Fuchs succeeded in rearing muscle-Trichinae in a calf, and 

 they found three female intestinal Trichinae in a goat, but 

 apparently no muscle-flesh-worms, althougth twenty-seven days 

 had elapsed since the first feeding with trichinised rabbit's flesh. 

 In three sheep on which I experimented no trace of Trichinae 

 could be found. There is no practical need for any further experi- 

 ments on herbivora, for it is quite clear that, in their natural 

 state, herbivorous mammals can seldom have an opportunity of 

 infesting themselves, whilst the reverse is the case with 

 swine, carnivorous mammals, and ourselves. Because many 

 quadrupeds become trichinous, it does not follow that all 

 mammals are liable to be infested. In the case of most 

 parasites we find the species limited to a larger or smaller 

 number of hosts. On the other hand, in not a few cases, the 

 range of the entozoon is limited to a single territory or host. 



In conducting the experiments above mentioned I was 

 assisted by Professors Simonds and Pritchard, of the Royal 

 Veterinary College. As they were the only researches con- 

 ducted on any considerable scale in England, I subjoin a few 

 details of them. Dr Thudichum's experiments were, I believe, 

 confined to rabbits. 



Exps. 1 and 2. On the 15th of March, 1865, an ounce of 



