14 Prof. G. Gulliver on the Raphides of British Plants. 



doubt they are of use both for food and manure. In such plants 

 as Lemna minor there is a store of phosphate of lime and starch, 

 just the kind of nutriment that young growing animals would 

 want; and the abundance of crystals in the ovary and testa 

 of Compositse seems to be connected with the nutritious properties 

 of the seeds. Thus we perceive one of the means by which such 

 humble plants are important in nature. It has long been known 

 how greedily water-fowl feed on the common duck-weed ; and, 

 making sure of the identity of this plant by the raphides, I have 

 found it in the stomach of young water-rats. 



Though the term ' raphides ' has been used indiscriminately 

 for all kinds of crystals in the tissues of plants, it will be confined 

 below, in accordance with its etymological import, to the acicular 

 or needle-like forms, and all the others will be noted simply as 

 " crystals." The former are known to be composed chiefly of 

 phosphate of lime, and some of the latter of oxalate of lime ; but 

 we are still ignorant of the composition of a great number of 

 these crystals. 



From my notes, extending over six years, of dissections of 

 several hundred plants, I find that raphides or crystals were 

 seen in the following Phanerogamia, but not in a much larger 

 number; so that they were not detected, though often looked 

 for, in many other orders which are not mentioned here. The 

 names of the plants are taken from the fourth edition of Prof. 

 Babington^s excellent * Manual of British Botany.' 



Caryophyllace^. — Silene Armeria. Square or cubic crystals, 

 in clumps j^Va ^°^^ diameter, in the ovary. The only plant of 

 the order in which I have seen crystals. 



ONAGRACEiE. — Truc raphidcs occur in such abundance as to 

 be quite characteristic of this order among the net-veined class. 

 All parts of the plant abound in them ; so that by these alone 

 a minute fragment of it may be easily distinguished from 

 Lythracese and Haloragacese. There were examined seven spe- 

 cies of Epilohium, three garden ones of (Enothera, and Circeea 

 lutetiana. The willow-herbs should be useful and often easily 

 available for manure. 



RuBiACE^. — Raphides common in this order, but less plenti- 

 ful than in Onagracese. They may be generally seen in the ovary, 

 and occur in the corolla, leaves, and other parts ; and were found 

 in Shei'ardia, Asperula, and in six species of Galium, which in- 

 clude all that were examined. It is remarkable that raphides 

 are common in the corolla and young fruit and scanty in other 

 parts of Galium Mollugo, though plentiful also in the leaves of 

 its variety /S scabrum. 



CoMPOsiTiE. — Raphides are less common in this order than 

 other crystals, and I have only found them in the ovary or 



