612 DR. H. CHARLTON BASTIAN ON THE ANATOMY AND PHYSIOLOGY 



the development of the ova of Ascaris mysiax whilst the animals in which they 

 were contained were immersed in oil of turpentine ; whilst Professor Aitkex says he 

 has " seen the development of the embryo proceed in spirits of wine for about three 

 weeks before signs of vitality had ceased." In certain species of Ascaris it has been 

 shown by many experiments that the ova remain in fluid occasionally for more than 

 twelve months before they begin to exhibit any active signs of development. Many 

 obsen'ations also tend to show tliat the majority of young and immatm-e Nematoids are 

 enabled to survive under circumstances which rapidly prove fatal to the adults. Thus, 

 speaking of Tricliina spiralis, Dr. Cobbold* writes, "M. Davaixe kept the larvae alive 

 in water for a month, but the adult worms perished in cold water in about an hour. 

 Under ordinary circumstances Davaine's observations lead us to conclude that the adult 

 worms do not survive their hosts above six hours, but the larvae will live for a long time 

 in flesh which has already undergone putrefaction." Some of the statements made con- 

 cerning the tenacity of life in the adult animals are so marvellous as to appeal* incredible ; 

 thus OwENf states, " a Nematoid worm has been seen to exhibit strong contortions — 

 evident vital motions — after having been subjected above an hour to the temperature of 

 boiling water with a codfish which it infested." Whilst according to Dr. AiTKEx:f, 

 MiRAM has seen specimens of Ascaris acus from the pike " become dry, and remain 

 sticking to a board, where they would revive again by being placed in water ; and in 

 some instances they would move a part of the body which had imbibed the fluid, whilst 

 the remaining part continued shrivelled up and adherent immoveably to the boai'd;" and 

 he further adds, " I have seen the very same results in the Ascaris which infest the 

 peritoneal covering of the mackerel." With regard to such powers possessed by these 

 animals I can myself say nothing. 



Passing now to the Anguillulidce, I may state as the result of many experiments with 

 these, that the power they possess of repairing injuries seems very low. I have cut off' 

 portions of the posterior extremity of the body of Enoplns communis, and though I have 

 watched the animal for days after could never recognize any attempt at repair. And, as a 

 general rule, when the bodies of any of the larger marine species are severed, both frag- 

 ments of the body will continue to move for from three to five days, though during this 

 time neither of the cut extremities shows the slightest signs of repair. For the last day 

 or two the fragments move only when irritated, and finally they cease to respond even 

 when roughly touched §. Within twenty-four hours of this time their bodies may be seen 



* Entozoa, 18G4, p. 3-4. t Lcct. on Comp. Anat. 1855, p. 116. 



% Science and Practice of Medicine, vol. ii. p. 126. 



§ It scorns possible that in some cases the anterior half of the body may survive much longer from a consi- 

 deration of the following facts. On April 5, 1864, 1 found in a wide-mouthed bottle containing saltwater and 

 a very small quantity of a filamentous green seaweed, the anterior half of a specimen of Oiichohimiis vulgans, 

 quite active in its movements, though presenting no traces of repair. It seems almost certain that the injury 

 to this animal must have been done on or before the 24th of the preceding month (March), since the water and 

 weed were put into the bottle on that day, and had not been interfered with in the meanwhile. Xeither were 

 there any larger animals in the bottle capable of biting the OiicJiolaimus in two. 



