=148. Starch grains formed in the chloroplasts.=—During photosynthesis the starch formed is deposited generally in small grains within the green chloroplast in the leaf. We can see this easily by examining the leaves of some moss-like funaria which has been in the light, or in the chloroplasts of the prothallia of ferns, etc. Starch grains may also be formed in the chloroplasts from starch which was formed in some other part of the plant, but which has passed in solution. Thus the functions of the chloroplast are twofold, that of photosynthesis and the formation of starch grains. =149.= In the translocation of starch when it becomes stored up in various parts of the plant, it passes from the state of solution into starch grains in connection with plastids similar to the chloroplasts, but which are not green. The green ones are sometimes called _chloroplasts_, while the colorless ones are termed _leucoplasts_, and those possessing other colors, as red and yellow, in floral leaves, the root of the carrot, etc., are called _chromoplasts_. =150. Photosynthesis in other than green plants.=—While carbohydrates are usually only formed by green plants, there are some exceptions. Apparent exceptions are found in the blue-green algæ, like oscillatoria, nostoc, or in the brown and red sea weeds like fucus, rhabdonia, etc. These plants, however, possess chlorophyll, but it is disguised by another pigment or color. There are plants, however, which do not have chlorophyll and yet form carbohydrates with evolution of oxygen in the presence of light, as for example a purple bacterium, in which the purple coloring substance absorbs light, though the rays absorbed most energetically are not the red. [Illustration: Fig. 70. Cell exposed to weak diffused light showing chlorophyll bodies along the horizontal walls.] [Illustration: Fig. 71. Same cell exposed to strong light, showing chlorophyll bodies have moved to perpendicular walls. Figs. 70, 71.—Cell of prothallium of fern.]