SEMEN. 



607 



It is probably no false inference on our 

 part, when we express the opinion that the de- 

 veloped seminal elements present every where, 

 and not merely in mammalia, birds, and fishes, 

 the same composition. Indeed, we do not 

 see any reason for assuming that this differs 

 even in cases where the proper fluid is want- 

 ing, and where it is only the spermatozoa 

 which constitute the seminal mass. 



Physiological office of the semen. Al- 

 though these results of chemical analysis 

 appear very important for the knowledge of 

 the nature and quality of the semen, yet 

 they afford but little assistance to an in- 

 vestigation respecting its modus operandi 

 in the process of fecundation. Indeed, it 

 would almost seem that an answer to such an 

 inquiry is farther off than ever, inasmuch as 

 we now know that a peculiar substance of a 

 specific quality exists, which \ve may indeed 

 consider as the bearer of the fructifying prin- 

 ciple, but that an effective spermatine does 

 not exist. The truth is, " the how" of the 

 fecundation is as far from our knowledge to- 

 day as it was thousands of years ago ; this 

 process is still enveloped in what we feel in- 

 clined to consider " its sacred mystery." It 

 would be different if we could prove that the 

 spermatozoa really yielded the material found- 

 ation for the body of the embryo ; that they 

 penetrated into the ovum, and were deve- 

 loped into the animal (which was the assump- 

 tion of Leuwenhock, Andry, Gautier), or else, 

 that they become metamorphosed into the 

 central parts of the nervous system. 



However, we are now convinced that all 

 these assumptions are without any found- 

 ation. The import of the spermatozoa must 

 be a very different one. But this is the very 

 point of which we know nothing with any 

 certainty. 



Leaving these views, which require no spe- 

 cial refutation, to oblivion, the following two 

 opinions on the nature of fecundation have 

 taken a tolerable position in our physiology : 

 One of them consists in the opinion that the 

 fructifying principle is lodged in the liquor 

 seminis ; the other, that it is centred in the 

 spermatozoa. Both, however, agree in this, 

 that an actual material meeting, an immediate 

 contact of semen and ova, is indispensable to 

 effect fecundation. The doctrine of an Aura 

 scminalis has long since, and most justly, been 

 cast aside. 



It was natural that the former of these two 

 opinions (viz. that which sought the essentials 

 of fecundation in the fluid and its mode of 

 action) should have found its advocates at a 

 period when the existence of the spermatozoa 

 was hardly known, or when, at all events, they 

 were supposed to be mere parasitic animal forms. 



Indeed, this assumption is at first sight sup- 



which, in a certain degree, form a medium between 

 animals and elementary parts of animals, seems en- 

 tirely to forget that it is only the morphological 

 condition, which can characterise a constituent of 

 the body as such. The physiological comportment by 

 itself ought not here to be taken into consideration 

 at all. 



ported by arguments of a seductive nature. 

 The liquor seminis, it was thought, comes into 

 contact with the membranes of the ovum, and 

 transudes them. It mixes itself with parts of 

 the yolk, and enters with them into many 

 chemical combinations, which fit them for a 

 change in their capacity for organization, for 

 the formation of cells, and for the development 

 of the embryo. This opinion did not, indeed, 

 suffer at first from the recognition of the nor- 

 mal nature of the spermatozoa. It was in- 

 deed possible, as Surdach thought, to find in 

 this very circumstance a proof of the great 

 organizability of the semen, of the ready mode 

 of dispersing it, which such an operation upon 

 the ovum would a priori require. 



Even up to the present day this hypothesis 

 of the influence of the liquor seminis has not 

 met with any direct refutation, although, as 

 we shall see presently, it appears to us now, 

 for many reasons, less admissible than it did 

 to one of us formerly.* The presence of 

 certain elementary structures in the seminal 

 fluid cannot yet be connected with the part 

 which they are intended to perform. It was 

 indeed possible that the remarkable qualities 

 of these structures had reference to the semi- 

 nal fluid alone ; that they, as it were, formed 

 isolated, free, ciliated epithelia, and that they 

 were intended, by means of their movement, 

 to bring the liquor seminis into contact with 

 the ovum ; or, as Valentin supposed, that the 

 state of mixture of the semen, so readily dis- 

 turbed, was preserved in its integrity through 

 their motions. The circumstance of meeting 

 now and then with motionless spermatozoa 

 is not in itself sufficient to refute this con- 

 jecture. For it might be said that in these 

 cases such a provision might not be neces- 

 sary, or that the object sought might be gained 

 in another way, and that the spermatozoa 

 merely existed as morphological equivalents of 

 the moveable seminal fibres, without a similar 

 physiological importance. 



The following fact, however, appears to us 

 of more real importance, viz. that a liquor se- 

 minis is positively not at all traceable in many, 

 and especially not in many of the lower, ani- 

 mals, in worms, insects, &c. ; but that, on the 

 contrary, the whole mass of the semen is 

 formed by the spermatozoa alone. Another 

 reason against the former assumption is this, 

 that an action of the liquor seminis on the 

 ova would be impossible in many cases, 

 where, for instance, the fecundation takes 

 place in the water, and without any real act 

 of copulation, the semen being ejected from 

 the male animals, and then left to chance 

 whether it comes in contact with the ova or 

 not. 



Such facts speak too powerfully in favour 

 of a specific purport of the spermatozoa in 

 the act of impregnation to allow us to 

 venture to say a word in support of the 

 older assumption. In addition to this, it 

 must be granted that the spermatozoa in the 

 male individuals are, in a morphological point 



* R. Wagner, Physiologie, S. 38. 



