78 BARRINGTON MOORE Vol. Ill, No. I 



unlimed soils were living and apparently thrifty. The two on the limed sand 

 survived through the season, one with only one leaf, and made a small growth 

 about equal to those on the unlimed sand. The limit of endurance of alka- 

 linity by sugar maple is therefore probably less than .003 normal. The limits 

 of acidity have not been determined, but it has been found growing in Maine 

 in a humus with a hydrogen-ion concentration, determined by the Wherry 

 method (n), of Ph 4.5, or specific acidity of 300. 



The toxicity of the burnt lime showed almost as soon as germination 

 occurred. On the humus, probably on account of the surface crust, seedlings 

 came up on only about a quarter of the rows, except pitch pine, which came 

 up on about two thirds. On the sand and mixture of sand and humus germi- 

 nation was about the same as on the unlimed soils. But soon after germina- 

 tion a striking difference between limed and unlimed was apparent. By 

 June 24 half of the Jack pine and a third of the pitch pine on the sand were 

 unhealthy and shortly afterwards died ; four fifths of the pitch pine and more 

 than half of the Jack pine and red pine on the mixture of sand and humus 

 were sickly and soon died. On the humus the Jack pine was in poor condi- 

 tion, the pitch pine had many unhealthy, and of the red pine only a small 

 number were up. 



From the point of view of survival the sand had the least ill effects of 

 the three limed soils, and the mixture of sand and humus the most, though 

 the humus was nearly as bad. By the middle of the season the flat containing 

 limed sand and humus was almost bare, and the humus flat not much better. 

 One red pine was living on the humus by July 12, and on the sand and humus 

 all the pitch pine were dead by July 2. Records of the rate of growth on 

 the limed soils are consequently based on a much smaller number of plants 

 than those for unlimed soils. 



Toxicity of burnt lime, though marked throughout the season, seems to 

 have diminished somewhat in intensity by about July 17, or about 40 days 

 after the exposure of the soil to the weather. 



It is curious that the lime seemed to nullify to a considerable extent the 

 beneficial influence of the humus. This may be due, in part at least, to the 

 heavier application of lime received by the humus as compared with that given 

 the other soils of the series. 



The tops of a few individual plants showed the effect of the lime by 

 becoming nearly white, not yellowish white. The stems, particularly on the 

 sand and mixture of sand and humus, were short and crooked, and often the 

 plants were lying prone against the soil, though alive and growing. 



Root growth was very markedly affected by the lime. Back of the normal 

 colored growing tip the root became brown and shriveled, sometimes for its 

 entire length; often it would be unnaturally twisted, and in many cases the 

 upper part came out of the ground and lay on the surface, the stem of the 



