104 THE BOTANICAL MAGAZINE. [Vol. xxxrv. xo.m 



D. Area in cross section of tracheitis in Cryptomeria japontca 



Though we can measure the length of tracheids quite exactly, 

 the determination of area in cross section of them is difficult, because 

 of their irregularity of form and arrangement. I measured the number 

 of cells in a definite circular area with the radius of 2 mm. (area = 

 125664 /J- 2 ). Average area (A) of individual cells will be (125664^ N) 

 ffi. Table IX will show some of the examples (Art. Jap., p. (174), 

 Table IS 1 ). 



From the table we see that the change of area of tracheids 

 according to the age is in the similar relation to that of the length. 



E. Ray tissue in Cryptomeria japonica 



The ray tissue of wood of Cryptomeria consists, as a rule, of 

 uniseriate parenchymatous cells. Biseriate rays were met with several 

 times, and triseriate rays very seldom. Dimensions of the ray tissue 

 were used for the systematic purpose of coniferous wGod by some 

 anatomists as Shroder, 2 Gothan 3 and others, but Essner, 4 Barber 5 

 and others stated that they change according to the age. 



In Cryptomeria, the number of cells in height in each ray was 

 recorded as 2-22 by Fujioka, 6 1-21 by Iwaki, 7 but I found it to be 

 1—28, exceptionally more than 30. Measurements were made on the 

 number in question in tangential sections, of which two will be given 

 in the table X (X, age; H, number of cells). (Art. Jap., p. (176), 

 Table 21 3 ) We can see here also the variation according to the age, 

 though in some cases it is not very distinct. 



The absolute height of each ray cell was measured in tangential 

 sections. Kleeberg 9 described in Cedrus that, the absolute height 



1. A, No. VI; B, No. I; C, No. II; D, No. IX; E, No. X. 



2. Shroder, J. (1872) Das Holz der Coniferen.-- Dresden. 



3. Gothan, W. (1905) Zur Anatomie lebenden und fossilen Gynmospermen- 

 holze. — Abh. d. preuss. Geo!. Land. Berlin. 



4. Essner, B. (1882) Ueber den diagnotischen Werth der Anzahl unl Hohe 

 der Markstrahlen bei den Coniferen. — Abh. Nat. Ges. Halle, Bd. 16. 



5. Barber, C. A. (1898) Cupressinoxylon vectense, a fossil conifer from the lower 

 Greensand of Shanklin.— Ann. Bot., vol. 12. 



6. Fujioka., M. (1913) Studien iiber der anatomischer Bau des Holzes der 

 Japanisch Nadelholzbaume. — Jour. Coll. Agr. Tokyo, vol. 4. 



7. Iwaki, T. (1918) Microscopical distinctions of some Japanese coniferous 

 wood. — Bot. Mag. Tokyo, vol. 32. 



8. A, No. IV; B, No. II; C, No. IX; E, No. X; F, No. I. 



9. Kleeberg, A. (1885) Die Markstrahlen der Coniferen.— Bot. Ztg., Jg. 43. 



