25 



colour is green. All this concerns the isolated chloropliyll cur- 

 puscles as well as those lying in amoebocytes. 



2. Enclosures. Very often the protoplasm contains oiu;, sonie- 

 times more, rcfractive globules, 0.4 — 1 [y. in diameter, wliich appear 

 blue-green whcn the microscope is well adjusted (Fig. 5). Some- 

 times one can also find them within the chloroplast. These glo- 

 bules are not stained by I (in KI sol.); but by sudan III (in 

 alc. sol.) they become red, and gray-black by osniic acid. So tliey 

 are fat-globules, better: oil-drops '). No other enclosures were 

 ever to be found within the chloropliyll corpuscles (except, of 

 course, what is mentioned sub 3 and 4-); so no carbohydrates: 

 I (in KI sol.) caused only a diffuse brown-colouring of the 

 whole corpuscle, but nowhere any special colouring. 



3. TJw nucleus and pyrenoide. As I have mentioned already, 

 the chloroplasts are entirely homogeneous ; a pyrenoid was never 

 to be found. But now the nucleus! If one stains chlorophyll 

 corpuscles, killed with formol-alcohol (1 p. form. 40 °l^ + 9 p. alc. 

 64 %) and which have lost their green colour, with methylene- 

 blue, one will often find in them one or more sharply outlined, 

 refractive, blue globules and sometimes a more diffuse blue spot. 

 The sharply outlined blue globules (Fig. 38, 39) are doubtless 

 the originally blue-green oildrops, still occurring in the unstained 

 matter as well. By their refraction they simply concentrate 

 the pale-blue light in the field of the microscope, in the same 

 way as drops of ceder-wood oil do in a solution of methylene- 

 blue in water. Perhaps the more diffuse blue spots might be 

 nuclei ; they are smaller than the preceding ones and are always 

 situated near the middle of the corpuscle (Fig. 40, 41). When 

 the same material is stained with haemateine-eosine (de Graaf), 

 the oil-drops remain uncoloured, viz. blue-green; but sometimes 



1) In cousequence of the very small dimensions of those globules it may sometimes 

 be dilticnlt to detect their red or gray-black colour; when comparing them however 

 with normal (not stained) globules, the ditference is always distinclly marked out. For 

 comparing oue should also stain other fat-globules, for instance railk, with the same 

 substances; one will see then, that only the larger globules have a bright red or a 

 dark gray-black colour, but that the colouring of the globules, having the same dia- 

 meter as our oildrops, is just as weak. 



