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growth. No matter how close to the margin a mark was placed, 

 all the growth was outside of it. For instance, spaces one milli- 

 meter apart were marked on the pileus with India ink. On 

 examination a few days later, it was seen that all the growth had 

 taken place in the outer millimeter. The other spaces had not 

 increased in size. 



This manner of growth is unusual in other families of the plant 

 kingdom. In all higher plants, the zone of growth is located a 

 little distance back from the apex of the growing point. Also in 

 the agarics among the fungi, we find a method similar to the 

 higher plants in the elongation of the stipe. According to Miss 

 Douglas and also Schmitz, the most rapid growth is in a zone 

 slightly below the apex of the stem, and from this zone, growth 

 is less marked as the base of the stem is approached. But the 

 stems of the agaric and of the polypore seem to be different and 

 are not comparable from the standpoint of growth. In the 

 agaric, the hymenium is formed and the growth of the stem merely 

 raises this up above the ground where the wind may catch the 

 falling spores. In Polyporns liicidus, the stem is the first part 

 formed and is perfectly developed before the hymenial surface 

 starts to form under the pileus. If we are to compare the growth 

 in the two forms, we should compare it in the young pilei in both 

 cases before and while the hymenium is forming. In the agaric, 

 this will exclude the elongation of the stipe, while in the Poly- 

 porns, it will include nearly the whole development of the plant. 

 Whether the growth and development of any of the agarics is 

 similar to the method we have seen in Polyporns liicidiis is a 

 question. It is surely not in all cases for Atkinson (i) has shown 

 that in Agariais canipestris, there is an endogenous development 

 in the pileus in the early stages. The latter is very different from 

 the exogenous development in Polyporns Incidiis. Other forms 

 of agarics as Collybia and Cantherellus that have an exogenous 

 development of the hymenium may have a growth similar to Poly- 

 porns Incidus, but this can be answered only by observation and 

 measurement. 



Among the external conditions which may affect growth are 

 temperature, moisture, and nourishment. Temperature has a 



