Dec, 1906.] THE VICTORIAN NATURALIST. l49 



seems to have held that the different salts directly formed the 

 different tissue elements, and that the shape of the latter was 

 determined by the crystallizing tendency of the former (p. 159, 

 &c.) It is only a few years since atoms have been shown not to 

 be the ultimate units of matter, but to be capable of still further 

 subdivision into electrons, and to the scientist of days to come 

 Nageli's micellar theory may appear to be just as absurd and 

 erroneous as Grew's ideas do to us now. 



The remarks upon the contrivances for the dispersal of seeds, 

 and upon the function of the different parts of the fruit and seed 

 (pp. 1S6, 189, 191, 198), are especially worthy of notice, for in 

 many respects they still hold good, as may be seen by reference to 

 Kerner's " Natural History of Plants." The presence of stomata 

 in the epidermis of leaves is mentioned (p. 153), and Grew states 

 that these may serve for the admission of air and also for the 

 excretion of superfluous sap, so that apparently water-stomata had 

 been observed as well. 



As regards the phenomena of sexuality and reproduction Grew 

 clearly states that phanerogamic plants and flowers are herm- 

 aphrodite, and that the " globulets " or " vegetable sperm " 

 (pollen grains) fall upon the seed case (gynoecium) and so touch 

 it with " a Prolifick Virtue." Apparently the existence of 

 unisexual plants and flowers had not yet been noticed, which is 

 hardly surprising, considering that the entire matter was still in its 

 infancy. The existence of unisexual plants was, however, deter- 

 mined by Ray ten years afterwards, and the sexuality of flowering 

 plants was placed upon a scientific basis by the systematic 

 experiments of Camerarius within the next three or four years. 

 The usual tendency of the time was to institute rigid and artificial 

 comparisons with the known organs of animals (Mammalia), and 

 the attempt to make such an analogy obvious leads Grew to put 

 forward some very curious comparisons in regard to the organs of 

 flowers (page 173). Even here, however, a certain revolt is made 

 against the tendency then prevailing, thus: — "If anyone shall 

 require the similitude to hold in everything, he would not have a 

 Flant to resemble, but to be, an animal." 



Grew was the first to observe that different parts of plants 

 yielded different amounts of ash constituents, and that various 

 forms of crystals could be obtained by allowing the watery 

 extracts of the latter to slowly evaporate, while from the figures 

 given it is evident that he obtained in crystalline form several of 

 the commoner saline constituents of plants (Tab. 83), and indeed 

 recognized that plants contained marine salt (sodium chloride) 

 and also what he terms " essential salts," although these must 

 have also included others which are not essential. 



In treating of the colours of plants the deficiency of the 

 chemical knowledge then extant renders almost the entire dis- 



