196 The Ohio Journal of Science [Vol. XIX, No. 3, 



Finally, crucial proof of the ability of the underground- 

 parts of plants to retain their vitality when buried was furn- 

 ished at Kodiak when I found an old rhizome of Equisetum, 

 which I had exposed in excavation in 1915, that had put forth 

 new shoots the following year, as detailed in the first paper 

 of this series, this journal page 32. 



The plants which had thus recovered after having lain 

 dormant for three years beneath the ash covering were some 

 of the most characteristic species of the region, including: 

 Calamagrostis langsdorfii (fruiting), Equisetum arvense, Car ex sp. 

 (fruiting), Rubus spectabilis, Salixsp., Rhodiolarosea, Sanguisorba 

 sitchensis, Artemesia tilesii, Poa sp., Streptopus amplexifolius , 

 Cardamine umbellata, Cerastium sp., and Juncus sp. With the 

 root survivals were also numerous seedlings, sprung from seeds 

 that had lain dormant under the ash. Car ex and Sambucus 

 pubens were abundant in all stations. Polemonium acutiflorum 

 (from seed ?), Geranium erianthum, and Heuchera glabra were 

 also found but less commonly. 



CAUSE OF DORMANCY. 



There is little reason for supposing that the species found 

 as root survivals have any special ability to endure burial, 

 or that others in the same areas had succumbed, leaving only 

 the most resistent to survive. The areas in question were 

 not large. If larger areas with more varied habitats had been 

 exposed, the list of survivals would probably have been con- 

 siderably increased. The fact that this ability to recover 

 after such a period of enforced dormancy was shown by various 

 species of plants, directs inquiry to the physical conditions 

 of the environment which made survival possible. Unfortun- 

 ately not enough is known of the environmental conditions 

 to enable one to make any satisfactory hypothesis as to the 

 causal factors, but some facts bearing on the situation may be 

 enumerated. The first supposition would naturally be that 

 a low soil temperature was the responsible factor. But the 

 facts of the situation will hardly permit one to assign to it the 

 principal role in this connection. It must be remembered 

 that the Katmai district is south of the region .where the soil 

 is permanently frozen. 



The August soil temperatures at a depth of 30 inches were 

 found to vary from 38-56 F. in different situations. The 



