310 PERCY SLADEN TRUST EXPEDITION. 
Genus BATHYPATHES, Brook. 
11. Bathypathes patula, Brook. (Plate 41. figs. 5-9.) 
This form oceurs with straight axes, averaging in the present specimens 25 cm. in 
height. From the main stem arise 18-20 lateral branches, slightly alternating with 
one another, which, unlike those of S. affinis, are longest in the middle of the series, 
where they attain a length of 10cm. The unbranched base of the colony, 10 em. 
in length, also differs in being attached by means of a small expanded disc to some 
foreign body such as a shell or small stone. The corallum is thinnest just above 
the attachment, gradually swelling out to its largest diameter about the middle of its 
length. 
As in the genus Schizopathes, the polyps are divided into three portions, but differ 
in being further apart from one another and in having the tentacles less long in 
proportion. The anatomy is typical of the Schizopathine group and calls for no special 
description. 
In the various colonies obtained, the polyps show great differences as regards the state 
of sexual maturity. These can be roughly arranged in three stages. At first the polyp 
has the gonads small and but little developed, and its three component parts, the two 
*oonozooids ” and the “ gastrozooid,” stand up well separated from each other (PI. 41. 
fig. 6). Later, as the ova begin to form and enlarge around the longitudinal septum of the 
gonad-bearing divisions, these portions of the polyp gradually become swollen out into a 
sac. At this period the “gastrozooid” portion appears to degenerate, as in the third stage 
it is non-existent, while the “ gonozooids” have the appearance of two mounds or egg-sacs, 
the tentacles having disappeared. These mounds attain the considerable size of 3 mm. in ° 
length, and the ova show through the body-wall as large white lumps. The position of 
the gastrozooid is marked by a space between the mounds. The mounds themselves are 
double, being formed of the ‘‘ gonozooids” of the neighbouring polyps, which by reason 
of the swelling of the ova have grown closely together (PI. 41. figs. 7, 8). 
This last state, which occurred only in one colony, shows a curious feature. Two, or 
in some cases three, neighbouring branches of a side adhere together from their ends 
backwards over a considerable portion of their length (fig. 9). In sections taken across 
this region there is an actual concrescence accompanied by a good deal of breaking down 
of tissue elements. That this adherence is real is further borne out by the fact that in 
taking away the skeletal parts as a preparation for section-cutting, the adhering polyps 
do not split down the middle but tear away at the stems. Whether this fusion is a 
regular or necessary part of the process I am unable to decide. It is difficult to see what 
mechanism there is except chance to bring the branches into contact. 
The above-mentioned stages occur in separate colonies, and in each case the polyps of 
the whole colony have arrived at the same state of sexual maturity. It appears, then, that 
when the colony becomes ripe the ova are liberated by the rupture of the polyp-walls, 
and the colony in all probability dies. Our ignorance of the embryological portion of 
the life-history of Antipatharia is so complete, that no side light can be thrown on the 
phenomenon by other species. Nor can we say whether this is the normal mode of 
