igoy.] Records of the Indian Museum. 239 



Asexual reproduction. — The ''normal single individual" is, how- 

 ever, very rarely met with ; since in the large majority of cases 

 indications of approaching fission are evident. Indeed, speaking 

 strictly, I believe that such indications are always to be met with, 

 and that even in the specimen represented in text- fig. 2, the arrange- 

 ment of the nephridia and the lateral extension of the nerve-cord 

 (here unusually evident) indicate preparations for renewed division. 



Figure 3 shows a specimen which is slightly longer than the 

 above, has an additional nephridium, and is producing new seg- 

 ments posteriorly, as indicated b}^ the terminal minute new setae. 

 This — and the same applies to several of the figures referred to 

 in the following few paragraphs — was drawn originally to illus- 

 trate other points ; the nerve-cord is here not represented, but an 

 irregularity of the septa about the ninth and tenth segments prob- 

 ably indicates the production of new segments at this place. 



Figure 4 represents a considerably longer animal. A definite 

 constriction divides it into two halves, of which the anterior is in 

 exactly the condition of text-fig. 2 ; the posterior contains also three 

 nephridia, with an interval between the second and third, where 

 a lateral extension of the nerve-cord is beginning to grow dorsal- 

 wards. This posterior portion evidentl}^ only requires the elon- 

 gation of its fore-part and the addition of the first setal bundles to 

 bring it also into the stage of the animal represented in text- fig. 2. 



Figure 5 shows this elongation and addition of the first setal 

 bundles (directed from the first forwards, not perpendicularly 

 outwards) as having taken place. But in this and the subsequent 

 examples the two chief components of the compound animal have, 

 before separation, developed further than the already separated 

 individual of text-fig. 2, which seems to have become free at an 

 unusually early stage. There seems here to be a slight irregular- 

 ity in the development of the nephridia. 



Figure 6 shows, as measured by the number of segments and 

 the development of the nephridia, a more advanced stage than 

 the last, though the actual division into two is apparently more 

 remote. It shows a typical distribution of the nephridia ; and a 

 number of extremely minute, newly developing setal bundles, dis- 

 tinguishable only with the high power, afford a good demonstration 

 of the various positions where new segments are being intercalated. 



Figure 7 illustrates again the slight irregularities which may 

 occur in the time of appearance of the nephridia. This specimen 

 contains one nephridium less than the last, though the most ante- 

 rior setal bundle of the posterior component is better developed, 

 and the minute setae at the zones of budding are — or were in the 

 original specimen — rather more in evidence. In this, as well as 

 figs. 5 and 6, it will be seen that attention has been paid to the 

 irregularities of the skin surface at the sites of future division. 

 Figure i shows a very similar stage. 



The longest animal of which I have any note, was also the 

 only one in which reproductive organs were seen. Sexual and 

 asexual modes of reproduction do not, therefore, exclude each other, 

 Here the two chief components each consisted of three portions. 



