A STUDY IN MOEPHOLOGY. 
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serially homologous organs do not necessarily owe their resemblances to inheritance 
from the unspecialised organs of a remote ancestor, and I think that the presence of a 
distinct occular segment in Squilla compels us to recognise an homology between the 
stalked eye and an ordinary appendage, although it is no doubt true that all the 
groups in which stalked eyes occur cannot be traced back to a common stalked-eyed 
ancestor, and also true that the stalked eyes themselves cannot be traced back to 
ordinary appendages. 
The ocellus. 
This is present from the first Nauplius stage to the end of the Schizopod series. 
Explanation of Table I. 
This table is designed to show at a single view the condition of each appendage at 
each stage of development. 
For convenience I have included the compound eyes, the ocellus, and the labrum, 
but do not wish to imply that these structures are or are not homologous with ordinary 
appendages, and I have omitted the metastoma, although I have no doubt that this 
should be included in a list of the appendages. 
In the table the word “ same ” indicates that the condition of the appendage is the 
same as it was at an earlier stage, and does not refer to other appendages in the same 
vertical line. 
