NOTES AND ABSTRACTS. 



159 



Palm Stems, Their Growth in Thickness in the Tropics. 



By Gregor Kraus (Ann. Jard. Bot: Buit. ser. ii. vol. iv. pt. i. 

 pp. 34-44; 1911). This is a continuation of some previous work 

 published by the author eleven years ago. In the winter of 1893-94 

 he carried out a series of measurements upon a number of palms grow- 

 ing in the botanical garden at Buitenzorg with the following results. 



(1) Young palm-stems show a growth in thickness throughout 

 their length from apex to base, which is quite obvious and clear even 

 in the short interval of a few months. 



(2) The successive partial growths in thickness along the stem 

 from apex to base are, as might have been expected, unequal, although 

 no definite law can be stated for all cases. In the first Oreodoxa 

 examined the increase in growth is most marked above, and regularly 

 decreases towards the base. In RJwpalohlaste the reverse was found 

 to be the case. In Drymophoeus the absolute growth had taken 

 place exactly equally above and below after three months. A com- 

 parison of the growth after the first month and after the third month- 

 showed, however, that this relation can vary. In the second 

 Oreodoxa examined the greatest growth in thickness had taken place 

 in the middle of the stem. This local growth in thickness produces 

 the barrel-shaped swellings found upon the older stems of Oreodoxa. 

 The regular strong growth of the base produces the bulb-like swelling 

 of that region. 



(3) Alf. Moller made some measurements of palms in Blumenau 

 (Brazil), and found that these indeed grew in thickness, but to a 

 far smaller degree than was found to be the case by Kraus in Java. 

 He found, for example, that the stem of a Euterpe grew in two years 

 only as much as Kraus 's palm-stems had done in two to three 

 months. Upon what this difference depends is still uncertain. 



(4) For how long the growth in thickness of a palm-stem can 

 continue could not be satisfactorily studied by Kraus, but in an 

 Areca catechu of 15 metres height the stem showed tio increase in 

 thickness during two to three months. This period was quite long 

 enough for younger plants to show a very clear growth in thickness. 



(5) Lofty palm-stems, measured breast-high, showed no growth m 

 thickness during two to three months. 



Kraus points out that it is most desirable that these observations 

 should be continued upon the same palms used by him in 1893-94. 

 As he is unable himself to visit Buitenzorg again he gives in the 

 present article a detailed description of the plants used by him, so 

 that other observers who have the opportunity may carry on a fresh 

 series of measurements, upon these trees and study their growth 

 after the lapse of so many years.- — R. B. 



Pansy, A Fusarium Disease of the. By F. A. Wolf {Mycologia, 



ii. pp. 19-22; Jan. 1910; fig.).— Plants attacked died suddenly. A 

 dark, slightly sunken area on the stem near the collar ,of the plant, 

 and destruction of roots, so that only small portions of the main roots 



