414 MARION I. NEWBIGIN. 



ingly soluble. Solutions obtained from the digestive gland 

 are yellowish in colour, from the fseces greenish brown ; both 

 have strong red fluorescence. The spectroscopic characters of 

 the former solution have been already described by Dr. Mac- 

 Munn; the latter differs chiefly in showing less absorption of 

 the violet end, and a more or less distinct band in the neigh- 

 bourhood of the r line : the difl'erences are associated with the 

 absence or diminished amount of lipochrome pigment in the 

 solution from the fseces. The " liver" extract, as shown by Dr. 

 MacMunn, turns green on the addition of acid; the extract of 

 the fgeces, on the other hand, turns first bluish, and then green 

 on further addition of acid. 



Relation to Chlorophyll. — The resemblances to chseto- 

 pterin which have been incidentally noted in the above de- 

 scription tend to disprove the identity of " enterochlorophyll,'^ 

 and plant chlorophyll, but it may be well before proceeding 

 further to state more clearly the difficulties which the sugges- 

 tion has to encounter. " Enterochlorophyll," in the first place, 

 difl'ers from true chlorophyll in giving the peculiar green re- 

 action already described. Further, the solutions are much 

 more stable than those of chlorophyll. As is well known, the 

 decomposition of a solution of chlorophyll in bright light is a 

 matter of minutes, while even in obscurity the fading is rapid. 

 Detailed observations on the eff'ect of sunlight on entero- 

 chlorophyll were not made, but solutions did not show marked 

 change when left to stand in the diffused light of the laboratory, 

 and remained unaltered during months of standing in a cup- 

 board, while an extract of green leaves standing in the same 

 cupboard lost its green colour entirely. More striking is the fact 

 that, although the colour and spectrum of ^' enterochlorophyll " 

 solutions change on the addition of acid, the original spectrum 

 can be restored by alkali, and the process repeated any number 

 of times; this is impossible in the case of chlorophyll. The 

 addition of aqueous or gaseous hydrochloric acid does not 

 produce a precipitate, or only to a very slight extent, and if 

 precipitated the pigment shows the character of the original 

 enterochlorophyll. Gaseous hydrochloric acid when introduced 



