106 MR. E. 8S. GOODRICH ON SYLLIS VIVIPARA. 
Tt is with regard to its method of reproduction that this Syllid 
is of peculiar interest. In all the specimens I examined (about 
twenty) either ova, or embryos in various stages of development 
briefly described this viviparous reproduction, and stated that the 
embryos grow within the body-cavity of the parent to an advanced — 
stage, when they completely resemble the adult excepting in 
their smaller size and lesser number of segments. According to 
this observer, they then escape by the breaking-off of the hinder 
region of the parent’s body. 
Ehlers, in his large work on the Polycheta (1), gives an account 
of Krohn’s observations, and suggests that fertilization must take 
place by way of the nephridia. Since Krohn’s note, published 
more than 30 years ago, no confirmatory evidence has been 
given of viviparity in any Syllid, excepting for the mere mention 
of a case (Syllis incisa) by Levinsen (3). Malaquin, in fact, in 
his monograph of these Polychxta (4), throws doubt on the 
accuracy of the observations recorded by these authors. 
The figures herewith given will, I hope, place beyond doubt 
that we have here a truly viviparous Syllid. 
In Syllis vivipara the ova are produced only in the posterior 
third of the body, where they are shed into the eelom in com- 
paratively small numbers. Here they undergo development from 
before backwards, and as many as eighteen embryos may be 
found in one parent. The course of development seems to 
differ in no marked way from that pursued by other Syllids 
outside the mother. Malaquin’s figures of the stages in the 
ontogeny of usyllis monilicornis (4) would apply almost 
equally well to Syllis vivipara. As the embryos grow larger 
they have some difficulty in accommodating themselves within 
the parental body-cavity. They usually take up a longitudinal 
position, with their head directed backward, and extend along 
many segments through the incomplete septa. In fig. 1 (Pl. 13) 
is shown a worm the young of which must be almost ready to 
escape. They have fully acquired the parent’s form, differing 
from it only in size. The ciliain the rectum can be seen to work 
from behind forwards, as in the adult. 
We are naturally led to enquire how these embryos are 
nourished, and how the ova from which they have developed were 
fertilized. 
With regard to the first question, there can be no doubt what- 
y| 
were found in the ccelomic cavity of the posterior region. Krohn \ 
? 
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