586 • G. A. MAO MUNN. 



^^ yellow cells," it is fair to conclude that those of the 

 latter are also due to ^'yellow cells," and do not 

 belong intrinsically to the animal, which is the point 

 to be proved. 



So far, then, there are several pigments present, three at 

 least ; one represented by a chlorophyll-like spectrum, charac- 

 terised by the dominant band in red, and by others when the 

 chlorofucin is separated out, chlorofucin represented by sp. 7, 

 and a lipochrome, or lipochromes, represented by bands in the 

 violet half of the spectrum. The chlorophyll is, however, 

 more decomposable by caustic alkalies than is that of land 

 plants ; and it is now necessary to see whether it agrees with 

 Sorby's "blue" or "yellow chlorophyll." Sorby^s yellow 

 chlorophyll is found in Ulva latissima.^ 



In the following experiments it must be remembered that a 

 relatively large quantity of chlorophyll was present, and that 

 consequently the dominant chlorophyll band was much broader 

 than that in any of the above spectra. I did not boil the 

 Ulva, as Sorby directs, but merely extracted it in the cold 

 with absolute alcohol for three days in the dark. The result- 

 ing solution was a fine sap green colour with a blood-red 

 fluorescence, and gave in a suitable depth the following 

 measurements : 



There were also two other bands, one in blue green and one 

 in violet. But in order to compare this solution with the 

 chlorophyll constituent of Anthea's colouring matters, it is 

 necessary to agitate with bisulphide of carbon and examine the 

 latter solution. Putting now the measurements of the bands 

 of this solution, and those of the corresponding extract of 

 An the a side by side, we get : 



' Sorby, loc. cit., p. 453. Besides the h'pochromes there is in Anthea's 

 tentacles a pigment sohible in glycerine which gives barn's in the violet, whieli 

 I have described in my paper on tlie " Chromatology of the Actinisc," loc. cit. 



