ON WANDERING CELLS IN ECHINODERMS. 95 
tegration of hemoglobin, a process which Gaskell (No. 32, 
p. 88) and J. H. List, among others, have followed histologi- 
cally; so that I think we may conclude that such effete pro- 
ducts would not be reabsorbed into the system, and that 
we may fairly adhere to the view which is advocated by 
Kolliker, &c. 
It seems exceedingly probable that this process of excretion 
by means of wander-cells occurs in many other animals, and 
that many of the “ mucous” and pigment-cells, &c., described 
in epidermis may really be of the nature of wander-cells, 
whose onward progress has been stopped for ever by the re- 
agents of the histologist. For instance, many of the leeches 
must have a very active “pigment metabolism,” judging by 
their botryoidal tissue and branched pigment-cells. The fol- 
lowing quotation from A. G. Bourne (No. 20, p. 429) is not 
without interest : 
“Two varieties of connective tissue may intrude upon the 
series of epidermic cells, and actually force their way up to the 
cuticle, pigmented connective-tissue cells and capil- 
laries of the vascular system. No pigment is ever developed 
in the epidermic cells themselves.” The matter requires 
further investigation, but the one or two specimens in my 
possession make me hopeful that a positive result might be 
obtained. Shipley (No. 57, p. 19) considers that possibly in 
these animals wander-cells may collect effete products and 
carry them to the nephridial sacs, and there undergo degenera- 
tion, whence they are voided through the nephridium. This 
conclusion runs hand in hand with Vejdovsky’s (No. 58, 
pp- 111, 112, and 127) observations concerning the granules 
resulting from the disintegration of the chloragogen cells of 
Kiukenthal (No. 41), which get carried to the exterior through 
the nephridia. 
In Oligochetes, Ude (No. 59) considers that chloragogen 
cells are bodily carried to the exterior through the dorsal pores. 
I must own that his observations do not appear altogether 
satisfactory. 
Eisig (27) gives a very-full account of the utilisation of 
