46 Papers from the Marine Biological Laboratory. 
EXPLANATION OF FIGURES. 
The figures were all drawn with the aid of a camera lucida from 
specimens preserved in formalin and for the most part stained and 
then mounted in glycerine jelly. Stages necessary for study and 
drawing were secured by deluging with full strength formaldehyde at 
the moment required. Large spermatophores before ejaculation may 
measure 50 mm. in length. The process of ejaculation increases the 
length to over 100 mm. and to this should be added the sperm thread, 
which, when uncoiled and ejected, measures at least 150 mm. more. 
ABBREVIATIONS. 
Cc, cap. 
cT, cap-thread. 
HC, hyaline core; the outer stiff portion of the core only is referred to. 
Hc’, hyaline core; the inner, more liquid material that mixes with the water and disappears 
is referred to. 
MM, middle membrane 
mm’, middle membrane; the point of attachment to the outer tunic. 
mt, middle tunic; this extends orally only a little further than the sperm mass. 
oT, outer tunic. 
PT, point of turning of the middle membrane; during ejaculation the pliability of membranes 
is such that this point lags far behind the outermost tip of evagination. 
SF, spiral filament. 
SL, space filled with liquid; this space is inclosed by the outer and middle tunics on the 
outside and extends between these structures and the sperm mass and ejaculatory 
apparatus; as ejaculation takes place the space continues down the evaginating 
ejaculatory apparatus. 
ZM, sperm mass; this consists of a spirally coiled sperm-thread that uncoils during ejaculation. 
s, granular material in the space, SL. 
Puate I. 
1. Spermatophore as taken from the spermatophoric sac, X 10 diameters. The specimen 
has been drawn in sections and the connections indicated by dotted lines. Speci- 
mens just removed from the spermatophoric sacs frequently show the sperm mass 
entirely filling the aboral end to the tunic. It is common to have specimens in 
which the ejaculatory apparatus, which extends from point 2 to point 6, is closely 
coiled nearer the oral opening than was the case in this specimen. The numbers 
2, 3, 4, 5, and 6 placed along the side of this drawing indicate the positions of 
more highly magnified drawings that bear the same numbers. 
2. Oral end of the specimen shown by figure 1, X 63 diameters. The position is indicated 
by the side of figure 1 by the number 2. 
3. A portion of the specimens shown by figure 1, X 63 diameters. The position is indicated 
by the side of figure 1 by the number 3. 
4. A portion of the specimen shown by figure 1, X 63 diameters. The position is indicated 
by the side of figure 1 by the number 4. 
5. A portion of the specimen shown by figure 1, X 63 diameters. The position is indicated 
by the side of figure 1 by the number 5. 
6. A portion of the specimen shown by figure 1, X 63 diameters. The position is indicated 
by the side of figure 1 by the number 6. 
7. The oral extremity of a spermatophore at the beginning of ejaculation, X 63 diameters. 
The cap-thread has been stripped back so that it does not show in this figure. 
This frequently happens in handling the specimens before they are permanently 
mounted. Soon after this stage is reached, the cap bursts and the fragments 
disappear. The cone-like projections on the portion extending into the cap are 
formed by the outer portions of the hyaline core which becomes spread over the 
outer surface of the evaginating tube. They settle down and are not as prominent 
after ejaculation has proceeded some distance. 
