Mat 4, 1906.] 



SCIENCE. 



699 



Sir Thomas Hanbury's famous gardens in 

 Italy, and gives mucli importance to char- 

 acters of flowers and fruit, characters whicli 

 have been largely ignored in previous schemes 

 of classification because unknown. The genus 

 Cereus is divided into eighteen subgenera by 

 Berger. The studies of the speaker and of 

 Dr. Eose indicate that both in the old genus 

 Cereus and in other groups of the cactus 

 family, well-marked differential characters of 

 flower and fruit are coordinated with those of 

 the stem in such a way as to make the recogni- 

 tion of several new genera natural and con- 

 venient. After these introductory remarks, 

 the meeting was adjourned to the propagating 

 houses of the garden, where numerous living 

 specimens of Cactaceaj were demonstrated and 

 commented upon. Of the genus Cereus in 

 the current sense, various types representing 

 subgenera or possible generic segregates were 

 discussed. Among these were Cereus peruvi- 

 anuSj the proper type of the genus Cereus; 

 species of the Pilocereus group, with which 

 the older Cephalocereus is historically iden- 

 tical; Cereus Schottii of Berger's subgenus 

 Lophocereus; Cereus geometrizans, represent- 

 ing Console's genus My rtillo cactus; Cereus 

 Pringlei of Berger's group Pachycereus; 

 Cereus sorwrensis, representing Stenocereus, 

 also of Berger; Cereus triangularis, a species 

 much cultivated in the West Indies and south- 

 ern Florida, with large beautiful nocturnal 

 flowers, a member of Berger's subgenus 

 Mylocereus; Cereus grandiflorus, the best- 

 known night bloomer, belonging in Berger's 

 subsection Selenicereus; the curious Cereus 

 Greggii with slender stem and very large 

 tuberous subterranean part, representing the 

 subsection Peniocereus of Berger; the Central 

 American Cereus haxaniensis of the group 

 A cantho cereus; the Costa Eican Cereus 

 Gonzalezii, of Berger's subgenus Leptocereus; 

 and also representatives of Engelmann's sub- 

 genus Echinocereus. Other specimens were 

 exhibited to illustrate the genera Phyllo cactus, 

 Epiphyllum, Cactus, Echinocactus, Melocactus, 

 Ariocarpus, Pelecyphora, Bhipsalis, Opuntia, 

 Nopalea, and the curious Pereskia, with its 

 leafy, vine-like or shrubby stems. 



The meeting of December 12, 1905, was 

 held at the American Museum of Natural His- 

 tory, with President Eusby in the chair. 

 Thirty-four persons were present. 



The announced paper of the evening was by 

 Dr. Henry Kraemer and was entitled ' Some 

 Studies on Color in Plants and the Artificial 

 Coloring of Flowers.' The subject of color 

 in plants was considered first from a morpho- 

 logical and chemical point of view, and the 

 speaker performed various illustrative chem- 

 ical experiments involving changes of color 

 in liquid media. The results of numerous 

 experiments on the control of color in living 

 plants and on the artificial coloring of cut 

 flowers were given. Dr. Kraemer's paper will 

 be published in full in the Bulletin of the 

 club. The following is his abstract of the 

 more important results of his observations and 

 experiments : 



1. Unorganized or cell-sap color substances are 

 distributed usually in largest amount at the 

 termini of the branches, as in flowers and ter- 

 minal leaves, or in roots, or in both tops and 

 roots. Their occurrence in those portions of the 

 plant, which are young and growing, points to the 

 conclusion that they are not to be disregarded in 

 the study of metabolic processes. Goebel holds 

 a similar view. He says that it is ' very prob- 

 able that the feature of color which so often ap- 

 pears when the propagative organs are being 

 brought forth has some connection with definite 

 metabolic processes, although till now we can not 

 recognize what these are.' 



2. The distribution of the so-called flower color 

 substances in other parts of the plant than the 

 flower also points to the same conclusion, and that 

 the part which they play in attracting insects to 

 flowers, is, if indeed they have any function of 

 this kind, incidental rather than fundamental. 

 The fact that certain colored flowers, as in the 

 spruce and red maple of early spring, are polli- 

 nated by the wind, would tend to confirm this view. 

 The food in the nectar and pollen are no doubt 

 sufficient attraction for insects and other animals. 



3. The occurrence of chromoplastids in a reserve 

 organ, as in the tuberous root of the carrot, and 

 the similar occurrence of chromoplastids and of 

 reserve starch in the petals of the buttercup, lead 

 to the inference that the petal of the buttercup, 

 like the root of the carrot, has the function of 

 storing nutrient material. In each case cells con- 

 taining chromoplasts rich in nitrogenous sub- 



