C(ELOM AND VASCULAR SYSTEM OF MOLLTJSOA . 431 



Between the capillaries and unconnected with them — in the 

 connective tissue of both Astacus and Limulus — is a system of 

 spaces containing a coagulable fluid. (These spaces were de- 

 scribed and figured in Limulus in 1884 by Professor Lankester 

 in the ' Quart. Journ. Micr. Sci.') It is into this system of 

 spaces that the tubular nephridium which becomes the coxal 

 gland of Limulus opens. Hence these spaces are remnants of 

 the coelom^ elsewhere blocked up and obliterated by the swollen 

 veins which form the hsemocoel. The tubular generative glands 

 of Arthropods are to be explained as perigonadial coelom com- 

 municating with the exterior through modified nephridia. 

 Beddard's discovery of such a condition of the ovary and 

 oviduct in the earthworm Eudrilus is confirmatory of this 

 explanation. 



''The views which had been thus arrived at by Professor 

 Lankester, and very briefly indicated in the note in the ' Quart. 

 Journ. Micr. Sci./ 1885, p. 515, have received a startling and 

 demonstrative confirmation in Sedgwick's brilliant results as 

 to the development of coelom and hsemocoel in Peripatus, 

 published in the ' Quart. Journ. Micr. Sci./ February, 1888, 

 and announced early in 1887 to the Cambridge Philosophical 

 Society." 



To this brief statement I may now add that it has been for 

 some time my desire to obtain well-preserved specimens of 

 Lernanthropus, the remarkable Copepod with a tubular vas- 

 cular system containing haemoglobinised blood, first described 

 as possessing this peculiarity by Edouard van Beneden, and 

 subsequently figured and described in detail by Heider {' Ar- 

 beiten Zool. Inst. Wien/ Bd. ii, 1879) . It would be extremely 

 important to ascertain, if possible, whether the tubular vascular 

 system of Lernanthropus co-exists with spaces which can be 

 identified with the supposed haemoccel of other Crustacea, or 

 whether, as should be the case if my theory is correct, the 

 spaces in Lernanthropus, which are not in continuity with the 

 red vascular system, can be identified as " coelom," and dis- 

 tinguished from '' hsemocoel spaces." 



1 have failed to obtain Lernanthropus either from Plymouth 



