PRATT: CYCLOLOMA ATRIPLICIFOLIUM. 101 



The phloem groups, which vary in size and are sometimes very- 

 small, are associated with lignified or unlignified parenchymatous 

 tissue. 



The types of anomalous structure found in the Chenopodiaceae, 

 Amarantaceae, Nyctaginaceae and Tetragonieae, and in species of 

 Mesembryanthemum and Phytolacca, are not adaptive anomalies, 

 but merely cases of variation of design; for the abnormal features 

 may be various in the several members of a family, and even in 

 the different species of a single genus, and yet not be connected 

 with the ecological relations of the plants concerned, according to 

 Haberlandt ('14). He makes the following statement concerning 

 the place of origin of the secondary arcs of meristem: "According 

 to Morot, each new arc of cambium arises opposite a phloem 

 group and extends laterally on each side until it meets an older 

 cambial layer. Herail, on the contrary, maintains that each new 

 cambium begins to develop at one end as a lateral continuation 

 of an antecedent cambial layer; then it extends gradually across 

 the leptome, and sooner or later rejoins an older strip. Leisering 

 believes that both possibilities may be realized. " 



Anomalies have been found in many lianes as well as in certain 

 small shrubs and herbs, according to Haberlandt ('14), but Hill 

 ('01) has examined an anomaly in Dalbergia paniculata, a tree 

 native to south and central India. He states, the anomalous 

 structure is "extremely interesting and equally surprising for a 

 tree attaining the height of sixty feet." From a preliminary ex- 

 amination of the wood, Hill describes the appearance of the 

 anomaly in cross section somewhat as follows: narrow zones of 

 tissue (termed by Hill as "narrow zones of the nature of phloem") 

 and broad zones of woody tissue alternate in a radial direction. 

 The anomalous zones are traversed by narrow medullary rays. 

 The following statement in regard to the structure of the anomaly 

 in the stem of Dalbergia paniculata are quoted from Hill : " By the 

 examination of a transverse section it may at once be seen that 

 the narrow, abnormal zones are of the nature of phloem, which is 

 accompanied by a certain amount of cambium. This cambium 

 is situated on the side nearer the center of the stem and abuts 

 directly on the xylem elements. . . . The wood is made up of 

 the usual elements; that is to say, vessels, fibers, and parenchyma." 



