A. G., Cambridge, Mass., writes: "What American mor-phologists (see p. 379) would say that all structure was of leaf origin?" What have you in view?"

[It is of course well known to the students of Dr. Gray's works, that he follows the lead of Gaudiehaud in supposing that plant cells first unite to form a primordial organism which Dr. Gray calls a Phytomer, or internodal stem, and that leaf structure follows, - but Herbert Spencer supposes that the first effort of the vegetable cell is to organize as leaf-blade, and that all structure results from this effort. It is our belief that the greater portion of morphologists who have studied the two hypotheses prefer the latter, though the fact that so eminent a botanist as Dr. Gray prefers the former, will be naturally regarded as weighing heavity in its favor. - Ed. G. M].