10 The Ohio Journal of Science [Vol. XIX, No. 1, 



derived in part from the activity of nitrogen fixing soil bacteria, 

 and in part from compounds formed in the atmosphere by elec- 

 trical storms. This suggested solution of the nitrogen question 

 is of great interest in connection with our problem. 



TAAL. 



The return of vegetation to the slopes of Taal volcano in 

 the Philippines after the destructive eruption of January, 1911, 

 has been studied first by Gates^° and later by Brown, Merrill and 

 Yates^\ Although it entailed the destruction of many hundreds 

 of human beings, this eruption was, by comparison with that 

 with which we are dealing, a minor affair. The depth of the 

 ejecta on the slopes of the volcano is stated by Worcester^- to 

 have been only 8-12 inches, while at the foot of Katmai, eight 

 miles from the crater, the ashfall was eleven feet on the level. 

 It is clear, therefore, that the return of vegetation to Taal is 

 more nearly comparable to the recovery at Kodiak than to the 

 re vegetation of the mainland areas in the vicinity of the volcano. 



Gates reported that "more than 99% of the new vegetation 

 are seedlings," but the sterilization even of the volcano island 

 was by no means complete, "for in April, 1914, bananas were 

 fairly abundant and indicated quite well the positions of many 

 of the former houses" while several species of bamboo, which 

 are likewise exclusively culture plants unable to spread without 

 human assistance, were prominent. Since only three clumps 

 of bananas and none of the bamboo were present in October, 

 1913, the indications are that these tropical plants have a 

 capacity for undergoing long dormant periods beneath the 

 ground, analogous to that found in the Katmai district (see 

 page 32). 



The investigations of Brown, Merrill and Yates suggest 

 that a larger proportion of the native plants likewise, may have 

 survived than was supposed by Gates. The most important 

 species in the new vegetation is a grass Saccharuni spontaneum, 

 which "has characteristic deep seated rhizomes." From 

 observations of the rate of growth, they believe "that the dense 



1° Gates, Frank C. The Pioneer Vegetation of Taal Volcano. Philip. Jour. 

 Sci. 9: Sec. C. 391-434. PL 3-10. 1914. 



11 Brown, W. H.; Merrill, Elmer D.; and Yates, Harry S. The Revegetation 

 of Volcano Island. Philip. Jour. Sci. 12: Sec. C. 177-248. PI. 4-16. 1917. 



12 Worcester. Dean C. Taal Volcano and Its Recent Destructive Eruption. 

 Nat. Georgaphic Mag. 23: 313-367. 1912. Citation on p. 350. 



