16 HEMICHORDATA CHAP. 
waste products discharged by the gland into the anterior body- 
cavity, though this view is not favoured by Willey. 
Reproductive Organs.—The sexes are separate, the repro- 
ductive organs consisting of a series of simple or branched 
glands which occur along the dorso-lateral lines of the anterior 
part of the body; being usually found throughout the branchial 
and generative regions and ending at the beginning of the 
hepatic region. The reproductive organs may pass into great 
extensions of the body-wall known as the “ genital wings,” 
specially developed in some species of Balanoglossus and Ptychodera 
(Figs. 1 A, 4). 
Stereobalanus canadensis, a species with long slit-like external 
gill-pores, is interesting in possessing a well-developed genital 
wing both dorsally and ventrally to the series of gill-pores of 
each side. 
Each reproductive gland opens by its own pore or pores 
directly to the exterior. Several glands and pores may occur in 
the same transverse section. 
According to Spengel there is no definite relation between 
the number of the reproductive organs and that of either the 
gill-sacs or the liver-outgrowths. The only definite segmenta- 
tion exhibited by Balanoglossus is-thus the division into three 
regions which is so distinctly shown by the arrangement of the 
body-cavities; though the gill-sacs may indicate an incipient 
further segmentation of the major part of the body. In this 
connexion it is interesting to notice MacBride’s statement ' that 
the body-cavity of Amphioxus develops in the embryo as five 
cavities, just as in Balanoglossus; the segmented part of the 
body being formed by a secondary segmentation of the third 
body-cavities. 
Regeneration.— Balanoglossus, like Phoronis (p. 30), possesses 
great powers of regenerating lost parts. The posterior part of 
the body is readily re-formed, while Spengel has shown” that 
even the proboscis, collar and branchial region can be regenerated, 
apparently from a fragment of the body. 
Genera of Enteropneusta.— Spengel, whose Monograph 
is indispensable to every student of the Enteropneusta, formerly 
1 Quart. J. Micr. Sci. xl. 1898, p. 601; xliii. 1900, p. 351. 
2 Monogr. p. 684, Pl. xxvi. Figs. 14-18 ; see also Willey, Zool. Res. iii. p. 245, 
and Dawydoff, Zoolog. Anz. xxv. 1902, p. 551. 
