The simplest carbohydrates known to occur commonly in plant tissues are the hexoses (see Chapter IV) having the formula C6H12O6 , which is just six times that of formaldehyde, CH2O. Also, it is known that formaldehyde easily, and even spontaneously, polymerizes into more complex forms having the general formula (CH2O)n; trioxymethylene, C3H6O3 , being a well-known example. Further, both trioxymethylene and formaldehyde itself can easily be condensed into hexoses, by simple treatment with lime water as a catalytic agent. Hence, it is commonly believed that formaldehyde is the first synthetic product resulting from photosynthesis, that this is immediately condensed into hexose sugars, and that these in turn are united into the more complex carbohydrate groups which are commonly found in plants.
