Oil liudies of ill e Juiifjermanniea'.. 127 



scalaris, Plagiochila asplenioidei^, Mastiijohryuia trilohutum, and 

 Radula complanata, the oil-like droplets, according to Pfelfer, 

 appear first at the leaf apex, and are formed later towards the leaf 

 base, but after dissecting numerous apical buds of Radula with 

 needles in water, I have failed to observe any such sharp distinction 

 between the apical and basal regions of the leaf as has thus been 

 indicated ; on the other hand, the dimness which ultimately results in 

 an oil body seems of fairly uniform intensity in both these localities. 

 In addition to the above, the following points are noteworthy : — 



1. The oil bodies of Radida complanata often exhibit very 

 active movements in their interior, somewhat like those in salivary 

 corpuscles, as was first pointed out by Dr Archibald Dickson, 

 Edinburgh. 



2. Very dilute acetic acid when applied accelerates this move- 

 ment. Turpentine and benzole, a short time after application, 

 increase the rapidity of the movements, but prolonged exposure to 

 these reagents results in fusion of the oil droplets. 



3. The colour of the non-emulsiform compound oil bodies of 

 Kantia tricliomanis is of a beautiful azure-blue shade, and this cavises 

 the leaves to assume a delicate bluish-green tint, which becomes 

 more marked if specimens are mou.nted for some time in very 

 dilute acetic acid. 



Regarding the physiological significance of these oQ bodies, the 

 results arrived at by Pfeffer may be stated as under : — 



1. They are not assimilation products, because they occur in 

 cells that never contained chlorophyll, e.g., in hairs or young leaves 

 before the formation of chlorophyll, as in Mast igohr yum trilohatwn ; 

 and again, since the oil droplets appear in cells at the tips of the 

 leaves before developing in basal leaf cells, the fatty matter cannot 

 Avander from the stalk to the leaves. 



2. The material out of which the oil bodies are formed, may 

 be glucose or some allied substance, although no reduction of 

 cupric oxide, except faintly in Lejjidozea reptans, is seen, there 

 being no storing of glucose ; that is, it becomes transformed into 

 oil as rapidly as it is formed. Similarly starch becomes oil in the 

 seeds of Pseony.* Fat may be present in a fine state of division 

 in the protoplasm, yet the oily droplets occur only in the cell sap. 



3. The oil bodies of Hepaticte once formed, behave as 

 "excretory" matter, having no latent assimilative value like starch 

 or glucose. Thus the cell sap in the cells of the sporogonium stalk 

 of Diplophylhim albicans gets diru before the sporogonium emerges 

 from the perichaetium, when it emerges the oil bodies are already 



* Pfeffer, Untersuchungcii iilicr Frotemkorncr ii. s. w. Jalir. f. iciss. But.., 

 BJ. viii. p. 507. 



