528 EXPEKIMENT STATION KECORD. 



Anioiiii' other physiolog-ical papers was one ]>y K. Goebel, on Regen- 

 eration in Plants, read by D. T. MacDougal. In this paper an account 

 was given of the regeneration in Bryophylluni, Begonia, and otl-y?r 

 plants in which various phenomena were shown by the repeated 

 removal of vegetative shoots from leaf buds, etc. In many instances 

 seedlings were shown to have the power of reproducing parts that had 

 been lost through various causes. The theoretical consideration of 

 the causes was noted. In the discussion which followed, T. H. Morgan 

 combated the hypothesis of Goebel that reg-eneration is due to the 

 presence of " formative stuffs" and of polarity. 



The Pearly Root Development of Tree Seedlings, an Important Fac- 

 tor in their Local Distribution, was the subject of a paper by J. W. 

 Toumey. The correlation ])etween the early root development and 

 the local distribution of seedlings was shown by means of a series of 

 lantern slides. The seeds of about 150 species of trees have been 

 planted and the seedlings examined to determine whether the root 

 systems exert an influence on the distribution of the species. Hickory 

 produces* a strong, persistent tap root, and these species persist on 

 account of these tap roots seeking crevices in rocks and penetrating 

 the soil deeply, so that they can flourish in poor, rock}" soils. On the 

 other hand, oaks do not have such a persistent tap root l)ut soon 

 develop secondary roots, and on this account oaks in geixeral require a 

 more moist soil than hickories. The tap root of the beech develops 

 strongh" for a time, l)ut in the course of a year a broad system of 

 lateral roots is developed, the tap root being checked in its further 

 growth. Similar root systems are found in the maple and red ash, 

 and these trees require a rich soil for their l)est growth. The sugar 

 maple develops lateral roots quite early, and in general trees which 

 develop strong lateral root systems in their early stages are not adapted 

 to growth on sterile soils. Attention is called to the fact that in 

 desert regions all the shrubby plants develop long tap roots. 



A. D. Selby described etiolated seedlings of the allig-ator pear {Persea 

 gratii<.xim<i). The etiolated and normal plants were of about the same 

 height, but structurally, as well as in color, considerable differences 

 were noted. In the etiolated seedling the leaves were strongly modi- 

 fied and greatly reduced in size, and considerable differences in stem 

 structure were also noted. 



W. F. Ganong pointed out that while most persons interested in 

 botany accept the statement that stamens and pistils are sexual organs, 

 it is denied by some of the newer morphologists, who hold that sexu- 

 ality is confined to the gametophyte within the embryo sack and the 

 pollen grain. The author showed "that the older terminology is cor- 

 rect, and that pistils and stamens should ])e viewed as sexual organs. 



The isolation of a hitherto unknown pigment found in the leaves of 

 Sarraceniapurpurra by W. J. Gies was reported. The same author 



