188 HIROSHI OHSHIMA 
specimens of H. tubulosa kept in a large box, the males 
emitted sperm in the form of long white threads at intervals 
of two to ten minutes. After some hours fertilized eggs were 
found on the bottom of the box. Edwards adopted 
Slenka’s live-box method and obtained fertilized eggs within 
four to ten hours. 
7. Newuy-suHep Eaes. 
The egg is slightly flattened, especially so on the side of the 
animal pole (PI. 8, fig. 4), as is known to be the case in C. nor- 
manifrom Newth’s observation (86, p. 633). Along the axis 
through the poles it measures about 300-85 p, and the greatest 
diameter as measured along the equatorial plane is about 340- 
400», most commonly 400. Externally the egg is covered with 
a radially striated gelatinous layer which is 50-72 thick. 
At the centre of the more flattened surface, the animal pole, 
the jelly canal can be distinctly seen. The egg is heavier than 
sea-water. 
According to Kowalewsky (17, pp. 2, 6) the egg of 
C. kirchsbergii is opaque with a greenish yolk, and is 
heavier than sea-water. The egg of C. planei is said to be 
four to five times larger than that of the former species, and, 
according to Selenka (45, p. 167), it is lighter than sea-water 
and floats immediately below the surface of the water. ‘The 
egg of C. frondosa is, as observed by Des Arts (2, p. 3), 
intransparent and of a red colour, with a distinct micropyle. 
Newth (86, p. 633) observed that the egg of C. normani 
tends to float with its animal pole directed upwards, and though 
no definite micropyle could be found the ‘ umbilicus’ of the 
follicle seemed to act instead. 
Remarkable records of large eggs are known among deep- 
sea forms, e.g. Enypniastes eximia has an ovarian egg 
of 3-0-8-5 mm. diameter, and in both Benthodytes gotol 
and Kuphronides depressa the ovarian egg measures 
2-5 mm. in diameter (Ohshima, 38, 1915, p. 214). Besides 
these cases, large eggs are met with in Cucumariidae, especially 
in those forms which are accustomed to care for their brood. 
