299 
2) Beranecr, Ep., Sur le nerf pariétal et la morphologie du 3me ceil des 
Vertébrés. Anatom. Anz., Jahrg. VII, S. 674—689. 
3) Francorre, M. P., Recherches sur le dével. de |’ épiphyse. Arch. de 
biol., T. VIII, Fase. IV, p. 757—821. 
4) Srrant & Martin, Die Entw. d. Parietalauges bei Lacerta vivipara u. 
Anguis fragilis. Arch. f, Anat. u. Phys., Anat. Abt., Jahrg. 1888, 
S. 146—164. 
5) Spencer, B., On the presence and struct. of the Pineal Eye in Lacer- 
tilia. Quart. Journ. of Micr. Sci., Vol. XXVII, p. 165—238. 
Nachdruck verboten. 
Duration of Motion of Human Spermatozoa. 
By GeoreE A. Pıessor, University of Pennsylvania, U.S. A. 
In the course of certain investigations undertaken as expert in 
connection with a case recently tried in the courts, questions arose 
relating to the length of time the seminal elements of man are capable 
of exhibiting their characteristic motion after discharge and of the 
effects of reduced temperature in arresting such vibration. A number 
of authors, as VALENTIN (1), KÖLLIKER (2), KRAUSE (3), LA VALETTE 
ST. GEORGE (4), SAPPEY (5), STÖHR (6) and others, agree that these 
cells may continue to move during 24 to 84 hours after death, in the 
fluids of the seminal tract. 
The duration of the vibration of these elements outside the body, 
and the latitude of the reduction of temperature within which their 
power of motion is retained, are less definitely stated. Hormann (7) 
observed movements after 72 hours; Leipy (8) states that under 
favorable conditions motion continues “for several days”. The most 
remarkable instance of the powers of resistance of these cells, however, 
is recorded in the well-known observations of ManrEGAzza (9), who 
found that spermatozoa of man may be subjected to a temperature 
of — 15° C without destroying their vitality; he further states that 
he kept human spermatozoa at 0° C for four days “sans que les 
spermatozoides eussent perdu leur vibratilit@”. A brief account of the 
results of my own investigations may not be without interest. 
The fresh spermatic fluid was placed on slides and carefully covered 
with large cover-glasses, the edges of which were painted with vasaline 
to guard against evaporation. The preparations so made were placed 
in small jars, tightly closed, and then subjected to reduced tempera- 
tures obtained by means of running water, in which the jars were 
