PROCEEDINGS OF THE MICROSCOPICAL SOCIETY OF LONDON. 125 



ccena, or Common Porpoise.' The subjects of the present communica- 

 tion, with one exception, were found in the lungs of the porpoise. Two 

 of them have been long known, and described by Rudolphi, Klein, and 

 others, under the names of Stronyylus inflexus and S. minor, whilst a 

 third, from the circumstance of its being found in company with the 

 S. inflexus, has, by many observers, and by Rudolphi particularly, been 

 considered as a younger specimen of that species ; and the fourth ap- 

 pears hitherto either to have escaped notice, or else to have been con- 

 founded with the last. The author's examinations of this Entozoon 

 lead him to consider it as a distinct species, and from certain peculi- 

 arities he has named it S. invaginatus. The largest mentioned was S. 

 inflexus ; this species occurred most abundantly in the bronchial tubes, 

 and in such numbers as almost to close them up, but many specimens 

 were found in the right ventricle and auricle of the heart, and in the 

 principal blood-vessels of the lungs as well. The average length of the 

 male is about seven inches, whilst that of the female is nine inches. 

 Our space will not allow us to enter into the minute anatomical details, 

 which will doubtless be published elsewhere. The next species was 

 found in common with the last, being twisted together in a knot around 

 them, both in the bronchial tubes and blood-vessels ; it has been noticed 

 as the young of S. inflexus, but on comparison the author finds that the 

 difference between the two is so marked, as to leave no doubt of their 

 being distinct species. Kuhn has described it as S. convolutus. The 

 third species is the smallest of the whole, and from this circumstance 

 has been named S. minor (Quekett). It occurred in the venous sinusses 

 of the heart, and in the cavity of the tympanum, and from living in 

 blood they were of a reddish hue. The fourth species was found on the 

 surface of the lung of a porpoise, the pleuritic investment of which 

 was raised into little tubercles about the size of a small pea ; and on 

 cutting into one of them five very long and slender white worms were 

 drawn out, one being much shorter than the rest, which was subse- 

 quently ascertained to be the male. On tearing a portion of the lung 

 a vast number of these cysts were found imbedded in its substance, 

 and in each one there were several worms coiled up in a very small 

 compass ; the cysts could be readily torn away quite entire from the sur- 

 rounding tissue with the worms in them. After describing and detail- 

 ing the structure of the male and female of each of the species above 

 noticed, the author concluded the paper with alluding to some 

 curious facts which present themselves for consideration. Entozoa, 

 from the time of their first discovery to the present day, have exhibited 

 more astonishing and wonderful phenomena than any other tribe of 

 animated beings, and perhaps, throughout the whole kingdom of nature, 

 no class has been so frequently the subject of opposite opinions, and on 

 the matter of their generation we are now nearly as much in the dark 

 as ever. In the various specimens mentioned above, there is, however, 

 the startling truth of one and the same species of Entozoon living in 

 such opposite media, viz., in blood and in air ; for it has been above 

 stated that S. inflexus was found in the bronchial tubes in the principal 

 blood-vessels of the lung, even in the heart itself, in the venous sinusses at 

 the base of the brain, and the cavity of the tympanum were literally 



