200 ORGANISED FLUIDS. 



spermatozoa not merely in the uterus and Fallopian tubes, 

 but also on the ovary itself. 



From these facts it is therefore evident that the spermatozoa 

 are essential to fecundity, although the precise manner in 

 which they are so is still involved in the greatest obscurity. 

 It is supposed by some observers, that they make their way 

 into the ovum itself: this notion is as yet without evidence 

 to support it. 



It would be most interesting to determine whether im- 

 pregnation could be procured by the artificial introduction of 

 semen, the animalcules of which were dead ; there is every 

 reason to believe that in the many cases in which the artificial 

 injection of the seminal fluid has been successful, the contained 

 spermatozoa were in a living condition ; and from all that is 

 yet known in relation to the animalcules, there is strong pre- 

 sumption to believe that the experiment referred to, viz. the 

 introduction of semen, the animalcules of which were dead, 

 would be unattended with success. 



One remarkable experiment of Spallanzoni, however, de- 

 serves to be referred to. Most observers agree in saying, that 

 the spermatozoa of the frog die after some hours of immersion 

 in water. It is known, however, that Spallanzoni succeeded 

 in fertilising the ova of frogs with spermatised water, con- 

 taining three grains of seminal fluid to eighteen ounces of 

 water, thirty-five hours after the mixture had been prepared, 

 and this, in a chamber with the thermometer at from 17 to 

 19 degrees ; and again, that in an ice-house, the thermometer 

 being three degrees above zero, the spermatised water pre- 

 served its prolific power for fifty-seven hours. 



Now, the tendency of this interesting experiment is cer- 

 tainly to prove the possibility of fertilisation occurring with 

 semen, the spermatozoa of which are dead : this inference 

 would appear however to be negatived by another ingenious 

 experiment of MM. Prevost and Dumas, who filtered the 

 seminal fluid and found that the fluid portion which passed 

 through the filter would not vivify the eggs, while the more 

 solid part, consisting of the spermatozoa, produced the results 

 peculiar to the seminal fluid. 



