BARLY DEVELOPMENT OF JULUS TERRESTRIS. 463 
out on the same species as Newport’s, confirm his account. 
In my opinion the conclusion to be drawn from these different 
accounts is that in different species of Chilognatha, and even in 
closely allied species of Julide, the hatching of the embryo 
takes place at very different stages of development. 
In 1841, Newport published his paper on the organs of 
reproduction and the development of the Myriapoda (11). 
This is the first paper containing any real information of the 
early stages in the development. On the first three days he 
describes the appearance of the yolk-spherules as seen through 
the chorion, and describes the whole contents of the egg as 
becoming firmer. On the fourth day he saw “ a little granular 
mass on one side of the shell” which he was inclined to regard 
as the future being. He made no further observations till the 
nineteenth day, when he describes the ventral flexure of the 
embryo within the shell. On the twentieth day he was able 
to make out six body segments. On the twenty-fifth day the 
embryo was hatched. 
I am inclined to think that the little granular mass which he 
describes on the fourth day was the first beginning of the blas- 
toderm. 
Nothing more was written on the early development of the 
Myriapoda till 1874, when Metschnikoff published his paper 
(9), which contains the greater part of what we know of 
Chilognath development. His fullest observations were made 
on Strongylosoma. He describes the segmentation, the forma- 
tion of the blastoderm, the formation of the ventral plate, 
the ventral flexure of the embryo, the segmentation of the 
mesoblast, and of the body, and gives a full description of the 
later stages. As I shall have to discuss his paper in detail I 
will not attempt to give a fuller account of it here. 
In 1877, Stecker published a paper (13) in which he describes 
the development of Julus fasciatus and several other species 
of Chilognatha. His account does not agree either with mine or 
with that of Metschnikoff. As his account has been fully 
criticised by Balfour (2), I will not refer to it here at greater 
length. 
