THE 
MONTHLY MICROSCOPICAL JOURNAL. 
AUGUST 1, 1876. 
I. — Ohservations upon Spermatozoa of Amphiuma tridactylum. 
By Christopher Johnston, M.D., Baltimore, U.S.A. 
(Taken as read before the Eoyal Microscopical Society.) 
Plate OXLV. 
Towards the end of April in this year we received through the 
kindness of Professor J. W. Mallet, of the University of Virginia, 
two very fine Amphiumas from New Orleans. The larger one, 
measuring 3 feet in length, died on the journey; but the other, 
30 inches long, survived, and on the 29th of April was made to 
exhibit the superb circulation of his giant blood-disks through the 
mesenteric vessels. 
The next day the animal was found, upon dissection, to be a 
male ; whereupon his organs were searched, and quantities of living 
moving spermatozoids met with. At first the size astonished us, 
notwithstanding our acquaintance with the average largeness of 
the histological elements of this other " friend of the physiologist ; " 
then the general movements absorbed our interest ; and lastly, the 
filmy modulations of a dehcate appendage of the " body " fixed our 
attention. Masses of the elements resembled bundles of needles ; 
but when separated, spontaneously or by art, they all glided along, 
either with an eel-like, coarse, flexuous motion, or with a gentle, 
arrowy progress. From the lower part of the efferent ducts the 
filaments obtained were completely rounded ; but the spermatozoids 
met with at higher points did not completely unfold, for the " tail " 
EXPLANATION OF PLATE CXLV. 
1 to 4, dry preparations. 
1 . Head of spermatozoid. 
2. Same, more highly magnified. 
3. Apex and apicial filament. 
4. Junction of head and body, with membrane beginning on the latter. 
Living spermatozoids. 
5. Head and projecting filament, body composed of two cords (and dorsal 
arch), and dorsal membrane. 
6. Entire spermatozoid, immature, its tail being still looped. 
7. Ideal, to show the efl^ect of the membrane in motion. 
Drawn from nature by the author. 
VOL. XVI. F 
