120 Prof. G. Gulliver on Raphides. 



bundles of raphides. Thus raphides are plentiful in the two 

 herbaceous species, and are replaced or represented by sphse- 

 raphides in the two shrubby plants. I have elsewhere (Quart. 

 Jburn. Microsc. Sc. for Jan. 1864) noticed the scarcity of ra- 

 phides and abundance of other crystals in trees and shrubs. 



Arace(B. — Prof. Balfour has for many years used the ovaries 

 of Arum for furnishing raphides to the pupils of his histo- 

 logical class, and Dr. Maclagan found these raphides to con- 

 sist of oxalate of lime. The question of the composition of 

 raphides is very important, and requires further research. They 

 have often been described as a form of phosphate of that earth. 

 Their abundance in the root of Smilaceaj led me to look for them 

 in the officinal extract of Sarsaparilla, in which no raphides could 

 be found, though it contained numerous minute square crystals, 

 some of which were distinctly seen to be such quadratic octa- 

 hedrons as are commonly formed of oxalate of lime. The dif- 

 ference between the raphis-cell and its surrounding cells is well 

 depicted in fig. 38 of Prof. Balfour's ' Manual of Botany.' Prof. 

 George Lawson, of Canada, informed me that while he acted as 

 histological demonstrator in Prof. Balfour's class at Edinburgh, 

 several years before 1859, he was frequently in the habit of 

 employing Lemna trisulca for the purpose of showing raphidian 

 cells*. 



Constancy of the Raphis-hearing character. — Raphides are 

 produced, as we have before shown, in all stages of the growth 

 of typical raphis-bearing plants, from the ovule to the seed- 

 leaves, thence through the ascending and descending axes, and 

 the appendages of the former and their modifications to the fruit. 

 So little effect has either the soil or the situation in which the spe- 

 cies flourishes on this important function of raphis-bearing, that 

 it will continue as regularly during the entire vigorous existence 

 of the plant as any common phenomenon of whatsoever kind in 

 the cell-life of that plant. ]3ut though these conclusions are 

 deduced from observations extending over the spring, summer, 

 and autumn of several years, and sometimes on plants from 

 various and dissimilar localities, the state of the raphides in the 

 winter season was seldom inquired into. Hence I have repeated 

 the examinations of such plants as could be easily procured be- 



* I have recently learned that Prof. Balfour long since observed the 

 abundance of raphides in various Aracese, as Colocasia odora, Rickardia 

 (Sthiopica, and Caladium viviparum. Prof. Douglas Maclagan discovered 

 the raphides in the ovary of Rickardia, subjected them to chemical ana- 

 lysis, and found them to consist of oxalate of lime. He looked at those of 

 Arum, and concluded that they also are oxalate of lime (Trans. Bot. Soc. 

 1861 ; Edinb. New Phil. Journ. new ser. xvi. 300). The raphides of Lemna 

 trisulca, which Dr. Lawson was the first to use in the class demonstrations, 

 were noticed in Prof. Balfour's ' Class-Book of Botany,' ed. 1855, p. 41. 



