October 9, 1914] 



SCIENCE 



511 



There are some reasons for believing that 

 the grinding effects of these huge masses of 

 rough pumice would be more destructive to 

 Nereocystis than to Alaria. The growing 

 region of Nereocystis is at the bulb, which 

 floats on the water. It is from this growing 

 region that the stipe elongates at its distal 

 portion and the fronds elongate at their base. 

 Serious bruising of this would undoubtedly 

 kill the plant. Alaria, on the other hand, has 

 its growing region near the base and the distal 

 end of the frond is usually more or less frayed 

 and ragged as a result of the action of tides 

 and waves. This kelp has continuous regen- 

 eration of the frond from this growing region 

 which is so far below the surface of the water 

 as to be safe from any direct injury by float- 

 ing materials of any kind, and it is possible 

 that individuals might be still living although 

 portions at the surface of the water looked 

 worn and dead. We found considerable beds 

 of Alaria at many places on the south shore 

 of Shelikof Strait and at a few places on the 

 north shore. A bed was found at Cape 

 Atushagvik only about 38 km. from the 

 volcano. 



At the time of our visit Alaria was much 

 more abundant in the region affected than 

 Nereocystis. There were many beds of pure 

 Alaria, but there were very few of pure 

 Nereocystis. There were only a few cases in 

 which the two species were mixed throughout 

 the bed. These facts can not, however, be 

 taken as indicating that the injury was greater 

 to Nereocystis than to Alaria, for they were 

 true outside of the region affected by the 

 volcano as well as in it. 



A good deal of injury to Fucus and other 

 plants growing in the littoral zone may also 

 have been done by the grinding effect of this 

 pumice. It is of course well known that Fucus 

 has restorative regeneration of its fronds," but 

 we could not detect that this was any more 

 common in the regions affected by this erup- 

 tion than it was in other portions of Alaska 

 or of Puget Sound. On several exposed rocks 



6 See Setchell, W. A., ' ' Regeneration Among 

 Kelps," Univ. of Calif. Pub. Botany, 2: 139-168, 

 1905, and the literature there cited. 



at Eussian Anchorage (35 km. from the 

 volcano) we found that practically all of the 

 growing Fucus was young, much of it not yet 

 producing spores. Among these young plants 

 were found the harder basal portions of old 

 fronds. 



It seems quite possible that the softer por- 

 tions of these plants had been killed by the 

 grinding of the pumice. On other rocks close 

 by, the growth of Fucus was abundant, and 

 the plants were vigorous and in fruit. In 

 addition to Fucus twelve genera of Algae were 

 found in the littoral zone at this point. These 

 were all fairly abundant and were in good con- 

 dition except that many of the red algag were 

 considerably faded. This, however, the writer 

 has found to be the case locally at several 

 points in Alaska and in Puget Sound. The 

 genera that we found in the littoral and upper 

 sublittoral zones at Russian Anchorage are 

 Ulva, Laminaria, Alaria, Agarum, Malosaccion, 

 Callophylis, Hildenhrantia, Corallina, Por- 

 phyra, Oloiopeltis. 



The maximum fall of ash resulting from 

 this eruption approximated 139 cm. Some 

 portions of the northern shore of Shelikof 

 Strait received as much as Y6 cm. The south- 

 ern shore of this strait received 51 em. in some 

 portions, and Kupreanof Strait received from 

 the latter amount down to 18 cm. Wherever 

 this deposit was heavy the result was that the 

 Algae in the flatter portions of the littoral zone 

 were completely buried. In Kupreanof Strait 

 and in the south shore of Shelikof Strait we 

 saw but little effect of the ash on littoral sea- 

 weeds. At Russian Anchorage near Cape 

 Atushagvik on the northern shore the results 

 of the ash were more evident. On a flat beach 

 at that place the covering of ash had resisted 

 the action of waves and tides and occasional 

 bunches of Fucus on rocks large enough to 

 reach the surface of this layer of ash was all 

 that was left of the littoral vegetation. Not 

 only had the 1912 crop of Fucus been buried 

 here but the 1913 crop had been seriously inter- 

 fered with by the covering of the stones that 

 would have served for anchorage. 



It seems probable that in some places suffi- 

 cient material has been deposited on the bottom 



