218 Mr. II. C. Williamson on a Bifid Earthworm. 



by distinct and separate rings applied to the eighty-fifth [in 

 this respect it differs from the earthworm wliich is the subject 

 of this article], and not by its bifurcation into two parts. A 

 small triangular membranous space was thus left on the 

 dorsal and ventral surfaces, between the junction of the 

 three rings. It was found that the large vessels, the diges- 

 tive tract, and nerve-cord divided at the eighty-fifth ring, 

 and were symmetrically arranged in each of the lateral ap- 

 pendages. Tlie generative organs were fully developed and 

 quite normal." 



Two abnormal earthworms are recorded by Professor F. 

 Jeflfrey Bell in the Ann. & Mag. Nat. Hist. 1885, vol. xvi. 

 pp. 475-477. " In the first specimen the left hind branch was 

 shorter than the right. Though the left branch looked like a 

 bud it was not really so, since as time wore on the difference in 

 size increased, and the left then was not only much the 

 smaller, but also much the less active. There were at first 

 no signs of a clitellum, but after two months there were 

 apparent indications of a clitellum. A short time after that 

 date it lost its tails, and soon after was found dead. 



" 1. It makes it quite certain that, like lizards with tlieir 

 tails, eartlnvorms may reproduce bilaterally what is ordinarily 

 only produced terminally. But this is only another way of 

 saying that earthworms are subject to a well-known and 

 widely diffused law. 



" 2. The fact that the clitellum only became apparent a 

 few days before the loss of the hinder end is positive; but 

 the events may or may not have any relation to one anotlier. 

 If they have, they only show that when the earthworm is 

 rcpi oducing parts of its body it is, pro tanto^ comparable to a 

 form reproducing itself asexually, a phenomenon which, so 

 high in the scale of organization, is, we know, not compatible 

 or contemporaneous with sexual reproduction. 



" The second specimen belonged to the species Lumhricus 

 foetidtts, and was dead when examined.'' 



In ' The American Naturalist,' vol. xxvi. no. 309, 1802, a 

 paper on " Bifurcated Annelids," by Professor Andrews, 

 appeared. Prof. Andrews gives five instances of this abnor- 

 mality in the species Liimhricus tcrrestris. Two of these are 

 the specimens described by Robertson and Bell, the remaining 

 three having been recorded by Dr. Horst, Asa Fitch, and 

 Dwight Marsh. Prof. Andrews in this article says : — 

 " Horst, in experimenting upon regeneration of lost parts in 

 earthworms, found one, 100 millim. long, with two tails, each 

 25 millim. long and quite normally formed. This was alive 

 when observed. Asa Fitch records iinding in his garden in 



