278 



Transactions. 



The phloem is a fairly wide band of tissue ; the sieve-tubes are of 

 small diameter, and there is a large amount of phloem parenchyma. There 

 are also small groups of sieve-tubes on the inside of the xylem. 



The xylem is a wide band ; it is formed for the greater part of very 

 regular rows of wood-fibres with slightly thickened walls. There are no 

 medullary rays. On the inside of the band of fibres there are a few small 

 vessels. 



The pith is composed of large thin-walled cells which have small inter- 

 cellular air-spaces between them. 



27. Myosotis Monroi Cheesem. i 



Habit. — This plant is a small perennial herb which is more or less 

 hispid with short, stiff, white hairs. The radial leaves are numerous, 

 |— 2 in. long, narrow obovate-spathulate, narrowed into a rather long slender 

 petiole, hispid with short, -stiff, white hairs on the upper surface, more 

 sparingly so beneath, and sometimes glabrous except the midrib. The 

 cauline leaves are smaller and narrower. 



Anatomy. 



Leaf (fig. 1). — The upper epidermis consists of large roundish or squarish 

 cells with thin walls, except the external, which are slightly thickened. 



--C 



1^-d 



Fig. 1. — Myosotis Monroi. Transverse section of leaf (x 175). a, uni- 

 cellular hair ; b, stoma ; c, palisade parenchyma ; d, spongy 

 parenchyma ; e, xylem ; J, phloem. 



A very thin cuticle is present. Numerous epidermal cells are produced 

 into long, stiff hairs with small protuberances on their outside walls. 

 Stomata are found on both surfaces of the leaf ; the guard-cells are small 



