in] OF ANTHOCYANINS 41 



especially in the papillae of the epidermis, the plastids tend to occupy 

 the base of the cell, while the soluble pigment is uniformly diffused. 



Investigations on the distribution of anthocyanins in fruits have 

 been undertaken by Borbas (38) ; and in seeds by Sempolowski (36), 

 Preyer (66), Brandza, Lindinger (76) and Coupin (82). 



Finally it may be as well to quote the Results which Gertz (19) has 

 given of a comparative examination of the localisation of anthocyanin 

 in members of many of the Natural Orders, and from which he finds 

 evidence of a certain amount of agreement between systematic relation- 

 ship and distribution of pigment. His results are shortly summarised 

 as follows : 



Helobiae. In Alisma, Butomus and Hydrocharis subepidermal, in 

 Vallisneria epidermal. 



Gramineae. Epidermal in Panicum, Oplismenus, Pennisetum, Cala- 

 magrostis, Set aria, Holcus, Weingaertneria, Catabrosa, Melica, Briza; 

 subepidermal in Pharus, Phleum, Alopecurus, Baldingera, Bromus, 

 Secede, Triticum, Avena, Aira. 



Aroideae. Subepidermal all through and similarly for Lemnaceae. 



Bromeliaceae. Chiefly in hypodermis but in some forms also in 

 epidermis. 



Commelinaceae. Epidermal. 



Juncaceae, Liliaceae and Amaryllidaceae. Subepidermal. In outer- 

 most scales of bulb of Allium often epidermal. 



Scitamineae. Epidermal. 



Orchidaceae. Epidermal in Cypripedium, Orchis, Epipactis, Limo- 

 dorum, Oncidium; subepidermal in Haemaria, Pogonia, Goodyera, 

 Microstylis, Reslrepia, Cattleya, Laelia, Dendrobium, Phalaenopsis. 



Piperaceae. Anthocyanin in subepidermal water tissue or in spongy 

 parenchyma. 



Salicaceae. Subepidermal all through. 



Betulaceae. Periodic anthocyanin in ground tissue. Permanent in 

 epidermis. 



Fagaceae. In general subepidermal. In certain species of Quercus 

 in hairs. In leaves of Copper Beech in epidermis. 



Moraceae. Subepidermal in Ficus. 



Aristolochiaceae. Epidermal. 



Polygonaceae. In young leaves chiefly epidermal. In older, sub- 

 epidermal, but types somewhat mixed so that localisation rather 

 indefinite, and still more indefinite in Amarantaceae. 



Nyctaginaceae. Aizoaceae and Portulacaceae. Epidermal. 



