CHANGES PRODUCED IN LUNG BY OLLULANUS TRICUSPIS, 145 



sessing two kinds of cells, one forming the ectoderm and 

 the other the endoderm, the endoderm being produced by 

 invagination. The Planuladse are hypothetical Mesozoa, 

 which ought to be formed at the expense of a multicellular 

 sphere resembling Magosphsera, in which the two cell-layers 

 are developed by delamination. The Dicyemidse will then 

 be placed amongst the Gastraeadoe as actual living types of 

 organisms with only two cell-layers. 



On the Changes produced in the Lungs by the Embryos 

 of Ollulanus TRICUSPIS. By Wm. Stirling, D.Sc, 

 M.D., Demonstrator of Practical Physiology in the 

 University of Edinburgh. (With Plate XL) 



Several years ago Prof. Leuckart described a small 

 nematode worm belonging to the family of the Strongylidse, 

 the Ollulanus tricuspis, which affects the cat. The adult 

 forms, male and female, are found in the stomach and in- 

 testinal tract even as far as the rectum.^ They, like the 

 intestinal trichinse, sometimes occur in such numbers as to 

 give rise to redness and ecchymosis of the mucous membrane 

 of the stomach. This worm is viviparous, and the young 

 embryos, like those of the trichina, migrate within their 

 feline host and become lodged in various organs, where they 

 themselves undergo and give rise to certain changes in the 

 organs wherein they become encapsuled. There are seldom 

 more than three embryos within each female, but the females 

 themselves often occur in great numbers. My attention has 

 been specially directed to the changes produced in the lungs 

 by the presence of these embryos of Ollulanus. 



I have had an opportunity of examining the lungs in two 

 cats so affected. Both cats were thin and emaciated and 

 were subject to frequent fits of vomiting. I only preserved 

 the lungs, so that I am unable to state the condition of any 

 of the other organs. Dr. Cobbold^ has found them in the 

 lungs and liver, Leuckart also indicates the pleura and 

 diaphragm as situations where they may be found. Dr. 

 Cobbold remarks that he has seen tens of thousands of them 

 occupying the lungs, the infested animal perishing by 

 the inflammatory action set up by their presence. Their 



' *Die Menschlichen Parasiten.' R. Leuckhart. Bd. ii, p. 102. 

 ^ 'Tile Internal Parasites of our Domestic Animals/ p. 125. 



