452 PROFESSOR J. STEPHENSON AND PROFESSOR HARU RAM ON THE 
The condition, therefore, is very similar to that of the young Pheretima ; and the 
same conclusion may be drawn from it regarding the origin of the gland. 
Conclusion. 
Typical examples of the lobate and tubular prostates of the Megascolecidse have 
been studied in detail. 
In both, the cells of the gland disintegrate to form the secretion, which takes 
the form of granules ; in the functioning gland, therefore, cell outlines are largely 
lost. Regeneration takes place in both by the formation of - discrete cells at the 
periphery of the gland. 
In the tubular form all the cells probably reach the lumen of the gland, and 
discharge directly into it. In the lobate form it appears that a large number of cells 
never reach the lumen of the intralobular ductule. 
The glandular mass is in neither case an invagination from the surface, but is 
derived from tissues of mesoblastic origin. This is shown, in the adult, by the 
relations of the glandular cells to the capsule and the connective tissue strands 
which attach it to the parietes ; by the occasional occurrence of supernumerary 
prostates in Pheretima , which are without connection with the exterior ; by the 
similarity of the young and still discrete gland cells at the periphery of the gland 
to the chromophil cells of the pharyngeal mass, which are of peritoneal origin ; and, 
lastly, by the development. 
REFERENCES TO LITERATURE. 
(1) Beddabd, F. E., A Monograph of the Order of Oligochxta, Oxford, 1895. 
(2) Benham, W. B., “ On some Edible and other new Species of Earthworms from the North Island 
of New Zealand,” Proc. Zool. Soc. Lond., 1904. 
(3) MichaElsen, W., “ Oligochaten von verschiedenen Gebieten,” Alt. Mus. Hamburg, vol. xxvii, 1910. 
(4) Spencer, W. B., “The Anatomy of Megascolides australis,” Trans. Roy. Soc. Victoria, vol. i, 1888. 
(5) Stephenson, J., “ On some Indian Oligochseta, mainly from Southern India and Ceylon,” Mem. 
Ind. Mus., vol. vi, 1915. 
(6) Stephenson, J., “On the so-called Pharyngeal Gland-cells of Earthworms,” Quart. Journ. Micr. 
Sci., n.s., vol. lxii, 1917. 
(7) Sweet, G., “On the Structure of the Spermiducal Glands and Associated Parts in Australian 
Earthworms,” Journ. Linn. Soc. Lond., vol. xxviii, 1900. 
EXPLANATION OF FIGURES. 
Fig. 1. Prostate of Pheretima hawayana, right side, as seen in dissection, x 10. 
a, b, c, the three lobes of the gland, in segments xviii, xix, xx, separated by septa 18/19 and 19/20 ; 
c.t., band of connective tissue binding down antero-internal corner of gland ; int., intestine. 
Fig. 1a. Prostatic duct and terminal portion of vas deferens of the same; these are normally covered 
over by the gland, the outline of which is indicated. x 14. 
pr. d., prostatic duct; v.d., vas deferens. 
