298 ON THE VITALITY AND DEVELOPMENT OF 



of potassium; chloride of ammonium; nitrate of potass; nitrate 

 of soda; carbonate of soda; and solutions containing riuth of 

 phosphate of soda ; sulphate of soda ; sulphate of magnesia ; 

 muriate of lime ; muriate of barytes, &c. All the other con- 

 ditions are alike : thus, in particular, the revivification from 

 concentrated saline solutions, except that the alkalies act as 

 excitants only in very weak solutions, and are destructive in 

 stronger^ 



The spermatic filaments of Fish, in their behaviour towards 

 water, correspond more with those of the Amphibia, but they 

 are by no means so long-lived. They are distinguished also from 

 those of the Amphibia, and of all other vertebrate animals, 

 by the greater delicacy of their structure, and by the difficulty 

 which exists in the finding of media favourable to their motion. 

 In general the same degree of concentration in the solutions 

 should be employed with them as with the spermatic filaments 

 of the Frog, except that it seems there are but few substances, 

 such as phosphate of soda in the proportion of 1 per cent., 

 and of sulphate of magnesia of the same strength, which are 

 altogether favourable to them ; but in these media I have seen 

 them in active motion for from six to twelve hours ; and such 

 solutions are perhaps adapted for the prolonged maintenance 

 in an active state of the seminal fluid of Fish. The revivifi- 

 cation after the action of water and of too concentrated solutions 

 takes place in them in the same way as in the spermatic filaments 

 of the Mammalia. Tiie caustic alkalies also act upon them as 

 excitants, though only in dilute solutions of | to | per cent., 

 for in stronger the filaments are immediately destroyed. 



When these facts are carefully considered, it is obvious 

 that it is impossible, with Ankermann, to regard the motions 

 of the spermatic filaments as the effect simply of endosmosis. 

 I consider that they are induced by molecular changes in 

 the interior of the filaments, which, though unknown, may 

 at present be compared with those in the muscular fibres, 

 and still more aptly to the ciliary organs of the Infusoria, 

 and to cilia in general. Should any one be inclined to the 

 opinion, that the revivification of filaments which have been 

 treated with water, by the application of concentrated solu- 

 tions, as of sugar, salts, albumen, &c,, as well as the restoration 

 of motion by means of water, after treatment with too concen- 

 trated saline solutions, are circumstances in favour of Anker- 

 mann's views, I would remark, that the Infusoria and cilia 

 also behave in the same way toivards saline and other solutions. 



The OpalincB — minute Infusoria from the rectum of the 

 Frog, and the cilia of the Frog's tongue — move in a solution of 

 common salt of 1 per cent, and of phosphate of soda of the 



