DR. C. A. MAC MUNN ON ENTEROCHLOROPHYLL, AND ALLIED PIGMENTS. 265 
Sp. 8. Petroleum-ether extract of this saponified enterochlorophyll showing only one 
band. 
Sp. 9. Alcohol-ether extract obtained as described under spectrum 7 in another 
experiment. 
The measurement of bands in the microspectroscope from which all the above 
spectra were mapped is attended with greater difficulty than in the chemical spectro¬ 
scope owing to the shortness of the spectrum ; hence some trifling errors of position 
may creep into the maps, which for that reason are not as reliable as the measure¬ 
ments given in this paper, each of which has been worked out by an interpolation 
curve from the readings of the photographed scale of the large chemical spectroscope. 
The remarkable agreement in these measurements—all of which were worked out 
independently of each other—shows that the wave-length method is the most reliable 
one, combined with the use of a spectroscope of moderate dispersion, 
Explanation of Plate 10. 
In Plate 10, I have endeavoured to show the appearances presented by entero¬ 
chlorophyll when fresh frozen sections of the “ livers ” of Invertebrates are examined 
under a power of about 320 diameters. The drawings do not show the relative 'pro-, 
portions of the constituent ceils, granules, &c., but merely the most typical appear¬ 
ances in each case. To save printing in too many colours, the latter have been made 
more uniform than they actually appear in the specimens. 
Fig. 1. Enterochlorophyll of Littorina littorea, principally in granules and dissolved in 
oil globules. 
Fig. 2. Ditto, from “ liver ” of Ostrcea edulis in the same form, the liver cells containing 
the pigment. 
Fig. 3. Ditto, from “ liver ” of Helix pomatia, the larger cells containing granules are 
probably the secreting cells, whose protoplasm is stained with the pigment, 
and some of which contain larger granules than others. 
Fig. 4. Enterochlorophyll of Limnceus stagnalis, in granules, oil globules, and secreting 
cells of “ liver,” some of which have their protoplasm diffusely stained with 
the pigment, and contain the latter also often in granules. 
Fig. 5. Ditto, from “liver” of Helix aspersa, the transition from green to brown and 
the presence of the large brown spherical bodies is very remarkable. Very 
few “ liver ” cells are here shown. 
Fig. 6. Ditto, from “liver” of Limax. The large epithelial liver cells are uniformly 
stained with the pigment, besides containing it in the granular form; in 
other cases oil globules containing the pigment are seen. 
MDCCCLXXXVI. 2 M 
