54 PROCEEDINGS OF SOCIETIES. 



Brighton and Sussex Natural History Society. 



April 23rd. — Microscopical Meeting. Mr. Haselwood, President, 

 in the chair. 



The receipt of eleven micro-photographs, by Dr. Hallifax, for the 

 Society's album, was announced, and a vote of thanks given to Dr. 

 Hallifax for the same. 



Mr. Wonfor on " Plant Crystals." 



In most of the manuals on botany or the microscope, certain crys- 

 talline bodies found within the cells of plants were designated by the 

 name Baphides, or needle-shaped bodies, a term inapplicable to some, 

 because they were not needle-shaped, and on the whole misleading, 

 because in the lists of plants generally given as containing them, it 

 would seem as though their appearance was an accidental circum- 

 stance in the economy of the plant, instead of a constant quantity, not 

 confined to one period of the plant's growth, but found in all stages 

 of its existence. 



The first to reduce to something like order and to indicate the 

 value of plant crystals in determining the differences between plants 

 of otherwise closely-allied families was Professor G. Gulliver, by 

 whom they had been arranged into the three groups — JRaj^Mdes, 

 Sphceraphides and Crystal Prisms. 



Baphides were transparent colourless crystals, needle-shaped, 

 and tapering to a fine point at each end, loosely connected in bundles 

 of twenty or more in oval or oblong cells of slightly larger dimen- 

 sions than themselves. The slightest pressure on the tissues of a 

 portion of a plant, when under examination, caused them to escape 

 from their cells. Examples could easily be obtained either by 

 making thin sections or simply tearing with needles a portion of 

 the tissues of any member of the balsams, woodruffs, evening prim- 

 rose, arum, orchis, and some of the iris family. 



Splicer aphides were more or less rounded, often spherical bodies, 

 made up of white or opaque crystals or crystalline matter. In some 

 the ends of the component crystals projected and gave them a star-shaped 

 appearance. They were much smaller than their cells, and, in some 

 cases, were thickly studded throughout the cellular tissue. This was 

 the case with many of the cactus family, some of which, when aged, 

 had their tissues so filled with them, as to render the plants very 

 brittle. It was mentioned that plants of G. senilis, reported over a 

 thousand years old, when sent to Kew Gardens, had to be packed in 

 cotton as carefully as if they were delicate glass or jewellery. The 

 fruit of the prickly pear was full of sphcer aphides, examples of which 

 were easily seen in the crane's-bills, elm, beet, spinach, or violets. 



Crystal prisms were found either singly, or two, three, or, at most, 

 four together, in combination in the same cell. While under a low 

 power rapjhides did not present angles or faces, crystal prisms j^re- 

 sented both ; instead, too, of tapering to a point at both ends, they 

 were wedge-shaped or angular. Some were three or four sided, while 

 others were octohedrons. They were larger than raphides, and were 

 not, as a rule, easily separated from the tissues in which they were 



