206 ADAM SEDGWICK. 
nucleated Infusorian with a mouth leading into a central 
vacuolated mass of protoplasm. 
The continuity between the various cells of the adult—the 
connections between the nerves and muscles and sensory epithe- 
lial cells, receive an adequate morphological explanation ; being 
due to a primitive continuity which has never been broken. 
Herbert Spencer’s view of the origin of the nervous system 
may perhaps not be so far from the mark as at first sight 
appeared. In any case the efforts to find out how the connec- 
tion is established between the nervous and muscular tails of 
the ectoderm and endoderm of the lower animals should be 
transferred to the earliest phase of the embryo, i.e. to the seg- 
mentation stages. 
Finally, if the protoplasm of the body is primitively a syn- 
cytium and the ovum until maturity a part of that syncytium, 
the separation of the generative products does not differ essen- 
tially from the internal gemmation of a Protozoon, and the 
inheritance by the offspring of peculiarities first appearing in 
the parent, though not explained, is rendered less mysterious ; 
for the protoplasm of the whole body being continuous, change 
in the molecular constitution of any part of it would naturally 
be expected to spread, in time, through the whole mass. 
In short, if these facts are generally applicable, embryonic 
development can no longer be looked upon as being essentially 
the formation by fission of a number of units from a single 
primitive unit, and the co-ordination and modification of these 
units into an harmonious whole. But it must rather be 
regarded as a multiplication of nuclei and specialisation of 
tracts and vacuoles in a continuous mass of vacuolated pro- 
toplasm. 
At any rate I may safely say that, so far as the individual 
embryonic development of Peripatus is concerned, the connec- 
tion of cell with cell is not a secondary feature acquired late in 
development, but is primary, dating from the very beginning 
of development. 
Since making these observations on the syncytial nature of 
the cleavage and gastrula stage of Peripatus capensis, I 
