182 THE BOTANICAL MAGAZINE. [Vo i. xxiv. No. 284. 



Each periderm consists of the outer cork layers of many 

 thin walled cells and the inner phelloderm of one — several layers 

 of thick walled cells, among which stone cells are found. 



In the middle part of the cortex, there are two kinds of 

 parenchymatous cells, the larger and the smaller (Phot. 1, PL VII). 

 The smaller are filled up with dark brown contents, while 

 the larger appear to have no contents. The latter are inter- 

 preted to be pecto-cellulosic mucilage cells* like those character- 

 istic to the cortex of Abies and Pseudolarix (Prantl 10). This 

 interpretation is based on the comparision with the similar 

 cells of the two genera in form and size of the cells and their 

 topographical distribution in the cortex, as well as the state of 

 preservation of the contents in dead twigs. 



Besides these two kinds of parenchymatous cells, there are 

 many large stone cells irregularly scattered and frequently found 

 in groups in this region. These groups of stone cells form 

 complicately entangled nests. The stone cells are roundish, 

 elliptical, wound, branched or of indescribably irregular forms 

 familiar to Ahietinese (Moeller 8, Prantl 10). 



There are comparatively large resin-reservoirs which extend 

 irregularly and end blindly within the cortex. The number of 

 their epithelial cell-layers is at least 3, more generally 5-7. 



In the secondary phloem, the nests of stone cells are more 

 largely developed than those in the outer region. They are 

 elongated vertically and are somewhat regularly fusiform. 



Besides these nests there are also vertically elongated thin 

 walled elements mixed with parenchymatous cells and stone cells. 

 Some of these elongated elements have the indication of a 

 single row of roundish sieve-fields on the walls. They probably 

 represent sieve-tubes. There is another kind of thin walled 

 elements, slightly wider than the sieve-tubes, and they are 

 clearly crystal tubes, each of them containing 1 or 2 rows of 

 minute rhomboidal crystals (Phot. 2, PL VII). These crystals 



* The general contents of characteristic mucilage cells of Abies and Pseudolarix 

 stain red with ruthenium-red, and blue with methylene-blue (pectin-reactions); and they 

 stain red with congo-red and turn blue with iodine and sulphuric acid (cellulose- 

 reactions.) 



