142 



Some Remarks upon Entozoa or Intestinal JVorms, with a List 

 of the Species at present known as occurring within the Bounds 

 of the Club. By William Baird, M.D. &c. 



The natural history of the Entozoa, or Intestinal Worms, is a 

 subject which has never yet, I believe, engaged the attention of 

 the Berwickshire Naturalists' Club. With very few is it a popu- 

 lar study ; to many indeed it is a repulsive one ; yet, when fairly 

 entered upon, how interesting it becomes ! Seldom have natu- 

 ralists in this country paid any attention to these remarkable 

 creatures ; and if, in the remarks which I now propose to make, 

 I shall induce any of the Members of the Club — a Club com- 

 posed essentially for the most part of practical out-of-door natu- 

 ralists — to devote some part of their time to the elucidation of 

 their history, I consider that I may have done science a service. 



I. With regard to their Origin. 



Intestinal worms are found in all animals, from man, the 

 monarch of creation, to the caterpillar which crawls under his 

 feet ; from the lion, which roams the forest in awful majesty, to 

 the fly which buzzes about his ears. In the human subject 

 they are found in all ranks, in the palace and the cottage, in 

 both sexes alike, in all ages, and not unfrequently even in the 

 new-bom infant. They infest almost every organ of the body 

 of the animals in which they occur. They are found in the 

 brain, the eye, and the different cavities in the head; in the 

 windpipe, in the lungs and blood-vessels of the chest; in the 

 liver and other organs of the abdomen ; in the kidneys, imnary 

 bladder, and under the skin ; the only organ, I believe, in which 

 they have not been found being that puzzling organ, the spleen*. 

 We can readily understand how they may be found in the 

 stomach and intestinal canal ; but it is very difficult to compre- 

 Tiend how they occur in the brain, the humours of the eye, or in 

 the blood-vessels. If the Harveian dictum, " Omne vivum ex 

 ovo," be correct, how came their eggs to obtain entrance to such 

 places as these ? The difficulty of accounting for such facts has 

 led to various conjectures amongst philosophers, and has given 

 origin to several theories of generation. The ancients believed 

 in spontaneous, or, as it is sometimes called, equivocal genera- 

 tion. They imagined that new living bodies sprang from the 

 putrefaction of old bodies ; that while organic substances by the 

 action of the chemical forces were undergoing decomposition, 



* One instance only has been recorded, and that the spleen of a species 

 of toad. 



