These theories are again supported by further examinations of the semen. Thus A. Schlemmer found, among a large number of apparently healthy individuals, six in whose semen not a trace of spermatozoa was discoverable; some, indeed, had recovered from genital affections, but their virile power was not diminished. Still more striking were the re sults of the observations of F. Kehrer: In 90 cases of sterility in mar riage, in which there Wa8 no pathological condition on the female side, he found absolute want of spermatozoa in the semen of 14 potent men. Only 8 acknowledged a former gonorrhcea. A still more positive proof is furnished by the further researches of A. Schlemmer made upon the se cretion of the testicles of men who had died suddenly. He found among them 8 men below sixty-eight years of age in whom no spermatozoa could be demonstrated.
While the examinations of the sperms of the living show us that azo ospermia can exist with potent men, the examinations of the cadaver show in addition that the seminal canals may be passable. Azoospermia, there fore, is not always to be accounted for by a defect in the expulsion of semen, but in a failure of its production. The causes of these functional disturbances of the testicles are further shown by researches of A. Schlemmer and A. Busch. Above all, the chronic wasting diseases are to be mentioned. In the testicles of a number of patients who had died of various diseases, Busch found spermatozoa in 13, very few in 13 other cases, and none at all in 11. In 45 cases of pulmonary phthisis 8 had many, 20 but few, and 14 no spermatozoa. Of other diseases diabetes and alcoholism are to be mentioned. Some drugs are also said to work to disadvantage. Some of the chronic diseases, however, would rather diminish, and would lead to sterility in this way rather than through azo ospermia. Severe acute diseases also exert a very unfavorable influence upon the production of spermatozoa. In 13 cadavers of individuals who died from acute diseases, Busch found in 9 many spermatozoa, in 3 but few, and in 2 none at all. Still more frequently, probably, various local diseases of the testicle and its surroundings lead to azoospermia. Of these gonorrhcea plays the principal role. This disease may in its course attack all the seminal paths, but most frequently invades the epididymis. Next there are inflammations of the testicle itself and of its sheath, which again may be of gonorrhceal origin, but may also occur as a consequence of constitutional syphilis. These venereal affections, however, are not the only ones that cause insufficient function of the testicle, but traumatic inflammations, hemorrhages into the tunics vaginalis, hydrocele, pro nounced varicocele, large scrotal herniie, may by strong and continuous pressure bring about the same result. Tuberculosis also and tumors,
when they attack both testicles, may lead to azoospermia. With these affections it may occur as a temporary trouble and may disappear as re covery takes place, but a prolonged duration of the disease will bring about further changes in the tissue and permanent sterility. We must also remember the premature senile atrophy of the testicle, an occur rence which does not take place so regularly nor at so certain a period of time as with the female sex. With some individuals the testicle may functionate till old age. The anatomical changes which as a rule are the fundamental cause of azoospermia, are degenerative processes which occur in two forms: fatty degeneration of the contents of the seminal canals or induration, cirrhosis, of the connective-tissue.
Some of the cases observed by Behrer make it seem probable that sexual excesses, masturbation, etc., can bring about this condition even without the assistance of the inflammations mentioned above. Of course if the remains of an inflammation that has run its course are not discov erable, and if the diagnosis is based entirely upon the history given by the patient, it is difficult to be positive on this point.
Deficient development of the testicle or its retention in the abdominal cavity may also bring about azoospermia instead of impotence, as Busch has observed. Some other cases again lead to the question whether azo ospermia could also occur without disease or failure in development. Cer tain cases of apparently entirely healthy men are report,ed where neither the history nor the most thorough examination could prove the existence of any defect or remnant of disease that would explain the existing azoosper mia. Although mistrust in regard to the patients' statements is justified in all these cases, yet the possibility of such a condition cannot be excluded. If such cases, as for instance Hirtz has described as idiopathic sterility, can be confirmed by further reliable observations, there could then be no doubt that with perfectly healthy individuals, uninterrupted sexual deaire, and regular performance of cohabitation, there may be no production of sper ntatozoa whatever. If the genitals, especially the testicles, prove normal, it is then indeed justifiable to think of an abnormality of the centre of func tion of the testicle. We would then have a congenital absolute azoosper mia. But this would contradict our usual views in two respects. It could not then be true that the formation of semen in the testicle is what causes the awakening of sexual desire, and secondly the centre of erection could not be identical with that of the production of semen, as is believed, but would have to be separate from it. Physiology gives no satisfactory explanation of this point.