134 ON THE DEVELOPMENT OF 
development. It still has only six legs, the fourth pair being 
represented by short rounded lobes; these lobes, gradually grow- 
ing, become jointed, and are furnished with claws and bristles; 
after which, the animal merely requires time to mature its several 
parts. Whether this is gradual, or assisted by a further moult, 
I am not prepared to state: it has been seen to perform this pro- 
cess in early life; so it is not improbable that it may do the 
Same, in a more advanced stage.* 
Finally, I figure a male Phowichilidium coccineum, and also a 
portion of a female, both fully matured; so that the several 
stages, from the germs, devoid of organs of any kind, to the 
perfect animal, may be compared, and their several points of 
difference and gradual growth be fully understood. 
Setting aside for a short space all that has been written on the 
subject of the anatomy of these animals as bearing upon their 
true position, especially by Quatrefages,t I think, if anything 
were wanting to show their connexion with the Crustacea, the 
mere phases in their development would be sufficient to decide 
the matter, and convince those who wish to remove them from 
this class of their error. 
The teachings of development must ever exercise a powerful 
voice in classification; and when we see so many instances, of 
the degradation of some animals and elevation of others, in con- 
sequence of the increase of our knowledge in this direction, we 
must all allow that, until we are fully conversant with the life- 
history of an animal, no matter how profound our other acquaint- 
ance with it may be, we have still much to learn. Nearly every 
animal that we can name possesses some wonderful story which 
requires unfolding as to its early life; and as our knowledge in 
this direction is extended, we trace step by step the connexion 
® Since writing the above, I have been so fortunate as to discover the moulted skin of 
the young Phoxichilidium which is cast by the animal before or at the time of leaving the 
sac of the Coryne: this cast-off membrane is extremely delicate an transparent, and 
shows the several limbs, &c., from which the animal had withdrawn itself, apparently 
without much damage to the exuvie. It therefore seems highly probable that the 
increase of growth in these animals is effected in a similar manner to that of other 
Crustacea, viz., by a series of moultings. We have seen two instances of this during the 
embryonic stages, and there is no reason why the process should not continue in after-life. 
+ See Quatrefages in ‘ Annales des Sciences Naturelles.’ 
