SPERMATOZOIDS. 325 



Spermatozoids. In August, 1677, a German student, 

 named Yon Hammen, 1 discovered the spermatozoids in the 

 human semen, arid exhibited them to Leeuwenhoek, who 

 studied them as closely as was possible with the instruments 

 at his command. For a long time, they were regarded as liv- 

 ing animalcules ; though now they are considered simply as 

 peculiar anatomical elements, endowed with movements, like 

 ciliated epithelium. These elements are developed within 

 the seminiferous tubes, by a process which has been most 

 elaborately and accurately described by Kolliker. They dif- 

 fer, not so much in their mode of development as in their 

 form, in different animals. We shall describe, however, only 

 the spermatozoids of the human subject, and we find that 

 the history of their development, as given by Kolliker, has 

 not been essentially modified by more recent researches. 



If we examine a specimen of the fluid taken from the 

 vesiculse seminales of an adult who has died suddenly, or the 

 ejaculated semen, we find that it contains, in addition to the 

 various accidental or unimportant anatomical elements which 

 we have mentioned, innumerable bodies, resembling animal- 

 cules, which present a flattened, conoidal head and a long, ta- 

 pering, filamentous tail. The caudate appendage is in active 

 motion, and the spermatozoids move about the field of view, 

 with considerable rapidity and force, pushing aside little cor- 



1 LEEUWENHOEK, Epistolce, Lugd. Batav., 1719, tomus i., p. 59. 



The discovery of the spermatozoids marks an era in the history of genera- 

 tion, as it was the first positive fact in opposition to the commonly-received 

 opinion that fecundation was accomplished by the aura seminalis, or vapor ex- 

 haled from the seminal fluid. It is curious, however, that we are not able to 

 state positively the correct name of the discoverer. Leeuwenhoek, from whose 

 original work the above reference has been taken, calls the name Hammius, 

 which is evidently a German name rendered into Latin. Milne Edwards calls 

 the name Ham. (Lemons sur la physiologic, Paris, 1863, tome viii., p. 339.) Lon- 

 get spells the name Hamm. (Traite de physiologic, Paris, 1869, tome iii., p. 

 781.) Sprengel (Histoire de la medecine, traduite par JOURDAN, Paris, 1815, tome 

 iv., p. 309) speaks of the discoverer as a young physician of Dantzick, Louis de 

 Hammen (probably Von Hammen). The name is known in the history of 

 physiology chiefly, if not entirely, from the letters of Leeuwenhoek. 



