Page:The Zoologist, 4th series, vol 1 (1897).djvu/182

154 the dark as to the morphological meaning of these pores." No relations are apparent between the dorsal pores and the nephridia. Michaelsen thinks the dorsal pores "have the function of nourishing the body and prevent its becoming unduly dry; it is certain that the cœlomic fluid is pressed out through the pores, and their occlusion is regulated by longitudinal muscles.... Perhaps in the Oligochæta the dorsal pores pass out the waste fluids, while the remaining excretory products are elaborated and passed out by the nephridia."

Thus we see that even now, notwithstanding the large amount of attention which has been paid to Earthworms during the past decade, we are very badly informed on many points connected with their economy; and there is great need that some one, with the necessary leisure, means, and scientific training, should investigate some of the details more fully. I have been able to make great progress with my work on the distribution and revision of the British Lumbricidæ, till recently almost totally neglected; and hope by the due publication of the new and interesting results to stimulate further research on the part of others.

Meanwhile, so far as the dorsal pores are concerned, they appear to be for the emission rather than the introduction of fluids; and are apparently lubricative, excretory, and protective. Their homology with certain organs found in other annelids does not seem to have been carefully ascertained; at any rate I know of nothing on the subject in English.