Armstrong : Trichina Spiralis. 



107 



beyond what I should call a seedling state — some wanting in stamina, 

 and others failing to find in their surroundings the requisites for 

 their continued existence. But in these plants we have also well- 

 authenticated instances of hybridity. Martins records the finding of 

 hybrids between Gymnogramma chrysophylla and G. Calomelanos, and 

 between G. chrysophylla and G. distans. Braun also found a hybrid 

 between Aspidium filix-mas and A. spinulosa, and I have no doubt that 

 if we were to take the trouble we might any of us very much extend 

 the list. 



Our greatest investigators — such men as Braun, Hofmeister, and 

 Sachs — are all firm believers in the sexuality of the higher crypto- 

 gams, and necessarily believers in the liability of these plants to 

 hybridise. My own views on this matter were formed years ago, and 

 before I had had the advantage of reading the works of these 

 distinguished men. I may have formed erroneous opinions on this 

 matter, but if I am wrong, I am at any rate v/rong in very good 

 company. 



TRICHIISrA SPIRALIS: 



OR 



THE PORK WORM. 



By Thos. Armstrong, F.R.M.S. 



The first record of the discovery of Trichina spiralis I believe to be 

 by Dr. Tideman, in 1822. Professor Owen next described, in 

 February, 183o, this human parasite. Mr. Hilton, of Guy's Hos- 

 pital, and Mr. Wormald, of St, Bartholomew's, had occasionally 

 noticed a peculiar speckled condition of the voluntary muscles of the 

 human frame, but do not seem to have ascribed it to this cause. The 

 case which aff*orded Professor Owen the opportunity of securing to 

 this country the honour of the discovery, was also observed by another 

 of our countrymen, Mr. Paget. Owen's view was, that the Trichina 

 is merely the first stage of an animal destined for further develop- 

 ment. Some of the first experiments to trace the origin of Trichina 

 in man, were performed in Edinburgh by members of the Physio- 

 logical Society ; specimens of the parasite were shown to the Society 

 in' March, 1853, by Dr. Gairdner, who declared that its whole 

 appearance was such as to strongly bear out Owen's theory. Gairdner 

 thought it probable that the muscle was only the hotbed of the ova 



