REPORT ON CEPHALODISCUS DODECALOPHUS. 27 



Nothing intervenes between their cavity and the ovigerous envelope, and indeed, as 

 formerly stated, they are so closely related that they are generally removed together in 

 dissection. No nerve-fibres could be traced from the central apparatus to these organs, 

 though appearances were favourable to such a view. Mr. Harmer, who independently 

 arrived at a similar conclusion with regard to the function of these organs, thinks the 

 pigment of an excretory nature. When the life-history of this peculiar form is more 

 completely marked out, it is possible that these oviducts may be found to be light- 

 producing organs. 



On extrusion the ova (PI. V. figs. 5, 6) are pure white, and either pyriform or rounded 

 in shape. Each is provided with a well-formed pedicle of the transparent investment, 

 truncated at tlie extremity for attachment. The diameter of the circular kind is about 

 0'55 mm., or including the short stalk 0-63 mm. In the more pyriform or longer forms 

 the total length (including the stalk) is about 07 mm., and the transverse about 0*5 mm. 

 The diameter of the contained yolk is about 0"36 mm. in the former kind, and in the 

 latter is nearly of the same proportional size, though more ovoid in outline. A large 

 space (perivitelline) existed around these eggs, but whether endosmose had occurred after 

 deposition, or otherwise, is at present unknown. The capsule is hyaline and structure- 

 less, presenting only a few wrinkles at the base of the stalk, which is hollow and 

 truncated at the tip. The opaque white central region is coarsely granular, as in the 

 intra-ovarian eggs. Each is attached to the wall of the chamber of the ccencecium by the 

 pedicle, though as now seen, that is after the action of spirit, many have become 

 detached. 



The products of the foregoing ova are yet undiscovered, though in all probability 

 they are motive embryos which carry the species to fresh sites on which to construct the 

 coenoecium. Such embryos had all been swept out of the chambers either before or after 

 capture, as no trace of them could be found in the preparations. 



The reproductive organs seem to be more largely developed in this genus than in 

 BJutbdo pleura, none indeed having been found in the latter by its discoverer. Professor 

 AUman, or subsequently in the living examples by Professor Sars. Professor Lankester, 

 however, was successful in finding a testis in " the form of a much elongated sac ending 

 blindly at one end and opening by the other to the exterior by a special pore." The 

 latter occurs near the anus. The position of the aperture of the male generative system 

 thus probably indicates what will be found in the living Cephcdodiscus, and it is possible 

 that the male organs are developed at a different period from the female in the same 

 animals, or that the males exist in separate colonies. In some of the sections of the 

 reproductive organs minutely granular masses like sperm sacs were occasionally seen, but 

 further examination gave no grounds for supposing that they were anything but im- 

 perfectly preserved contents of the ovaries. 





