270 
Amoebotaenia sphenokles 
into two at right angles to its former course, one branch rmrning to the 
apex of the rostellum {r .n .), and one down the margin of the scolex 
{s'.n'.) apparently to the anterior margin of the corresponding sucker. 
Each sucker would thus appear to be supphed by two nerves. The main 
rostellar nerve is in the form of an arc wdth the convexity directed 
towards the suckers. A thick branch is given off to the rostellum soon 
after it leaves the circum-rostellar commissure. 
Genital Organs. 
Each proglottis has a common genital sinus, regularly alternating, 
situated at the anterior sixth of its length, almost at its anterior corner 
(PI. XX, fig. 4). It is cyhndrical in shape with the inner end rounded. 
It has a breadth of 0-0127 mm., and extends 0-04 mm. into the pro¬ 
glottis, making an angle of 40° with the side of the worm. Into it open 
the cirrus and the vagina, not side by side as Magelhaes states, but one 
in front of the other, the vagina opening into the extreme end of the 
sinus, and the cirrus into the side some httle distance from the vagina. 
My specimens thus confirm Cohn’s description but not his figure : the 
latter indeed does not agree Avith his own statements, for he does not 
figure a genital sinus at all. The sharp anterior bend of the vagina 
after leaving the genital pore gives at first the impression that the sinus 
is situated much more posteriorly, and to this appearance is probably 
due Cohn’s statement that the pore is at the anterior third of the pro¬ 
glottis. 
Male Organs. 
According to Magelhaes, “ Le parenchyme des deux premiers anneaux 
ne presente aucune trace d’organes genitaux. Les organes males se 
montrent deja dans le troisieme anneau.” On the other hand Cohn states, 
“ Die ersten Zellhaufen, welcher die spater zur Entwdcklung gelangenden 
Genitalorgane bezeichnen, sind schon friiher vorhanden, als sich selbst 
die erste Proglottis deutlich absondert. Zwei solche Zellhaufen, durch 
ihre Farbung im Totalpraparat deutlich kenntlich, liegen noch im unge- 
gliederten Theil gleich hinter den Saugnapfen und in der Mittellinie.” 
My own preparations agree Avith neither statement. The first signs of 
male organs usually appear in the second segment, although I have 
seen dubious traces in the first. Of Cohn’s “ Zellhaufen ” behind the 
suckers I have been unable to find any trace. On the Avhole, the male 
organisms are first clearly recognisable as such in the third segment. 
It is possible that Avith the increasing age of the AA'orni, the earlier 
