ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 69 



l-4:th in. long — and wandering along the damp roots of grass, its 

 presence may readily be overlooked. 



The infection experiments proved that this mollusc was the sole 

 intermediary host of the fluke. The fluke is very prolific, but so long 

 as the ova remain in the liver they undergo no further change. In 

 artificially hatching them, the embryo is seen to leave the egg by the 

 sudden giving way of the operculum ; and once in water the cilia with 

 which the body of the embryo is covered come into action. The 

 free-swimming embryo has a spindle shape and is provided with a 

 double eye spot (two masses of pigment), and is very sensitive to 

 light. If the embryo comes in contact with a Limnceus truncatulus 

 it begins to bore into its shell, the head papilla becomes elongated 

 and sharp, and by a sudden movement the boring is effected, and the 

 body of the embryo passes into the snail. As soon as it gets into the 

 snail the body contracts, its outer layer is cast off', and it degenerates 

 into a sporocyst. By proliferation of cells lining the body-cavity 

 and of cells in the body-walls, masses of germinal cells are formed 

 from which the cercaria is developed. The sporocyst usually 

 developes in the pulmonary cavities of the snail and the parasite gets 

 into the liver, feeding on the liver cells. The cercaria is formed by 

 the rounded germ-masses becoming elongated, one end being pinched 

 off to form a tail. When the cercaria has escaped and become 

 encysted, it remains quiescent until swallowed by the sheep ; when, 

 the cyst being dissolved, the embryo fluke finds its way into the liver 

 ducts of the sheep. The real preventive of the disease is salt, a small 

 quantity of which will not only kill the larvae of the fluke, but the 

 Limnceus also. The salt should be scattered over all land where the 

 snail is believed to be present. 



Ankylostoma and Dochmius.* — P. Megnin, in examining a number 

 of dogs attacked by the anemia which decimates large numbers 

 annually in France, found that three apparently different species were 

 always present. One in which the buccal armature has straight 

 teeth answering to Dochmius trigonocepJialus of Dujardin ; another with 

 hooked teeth like Ankylostoma duodenale of Dubini, which has pre- 

 viously only been found in man ; and a third with hooked teeth, within 

 the inner pair of which is a small tubercle like Dochmius balsami of 

 Grassi = D. tuhceformis of Dujardin. 



As these three forms are constantly found living side by side in 

 the same host and contributing to the same disease, the author con- 

 siders that they represent one species in which the form of the teeth 

 probably varies more or less with age. 



New Flosculariae.— Dr. C. T. Hudson announces the discovery by 

 Mr. J. Hood of Dundee, of a very large and strange Floscule, new to 

 science, which he names F. Hoodii after its discoverer. 



It is no less than 1-lOth of an inch in length, and is therefore by 

 far the greatest of all the Eotifera, exceeding F. trifoUum as much as 

 that does F. campanulata. It has only three lobes, very short setfe, 

 a very peculiar outline to its trochal disk, and, strange to say, two 



* Bull. Soc. Zool. France, vii. (1882) pp. 282-9. 



