﻿534 BOTANICAL GAZETTE [june 



somewhere between 1:00 and 3:00 p.m., showing the influence of internal 

 factors upon transpiration. The rate of evaporation was determined by Piche 

 atmometers and transpiration loss by weighing closed bottles of water in which 

 the excised leaves were inserted. Leaves taken from the same plant at heights 

 of 13, 47, 71, and 100 cm. showed relative transpirational losses per unit area 

 of 100, 114, 103, and 86, or a somewhat smaller loss from the upper leaves 

 than from the lower ones placed under the same conditions. 



Burns 9 has compared the transpiration of Pinus Strobus seedlings grown 

 in nursery beds unshaded, half shaded, and full shaded, with the evaporation 

 from black and white atmometers, and has found a closer relation between the 

 transpirational losses and those from the black atmometer. The relative tran- 

 spiration was here for the unshaded, half shaded, and full shaded plants respec- 

 tively 0.0633, 0.0346, and 0.0088, from which he calculated the amount of 

 water transpired to be proportionately 21,8, and 1 parts. A further compari- 

 son showed the average green weight of the unshaded, half shaded, and full 

 shaded plants to be respectively 0.304, o. 166, and o.ooogm.; while the dry 

 weight was o. 063, o. 034, and o. 010 gm. ; that is, the dry weight of the shade- 

 less plants was 6 times^that of the full shaded, and twice that of the half shaded 

 plants. On the other hand, the nitrogen content in percentage of dry weight 

 was respectively 2.18, 2.70, and 6.89, or nearly 3 times as much in the full 

 shaded plants as in either of the others, showing that a large amount of tran- 

 spiration is not to be related to the absorption of ash constituents. Burns 

 concludes that his experiment indicates that differences in size and chemical 

 composition of these white pine seedlings must be sought along the line of 

 photosynthesis and assimilation, rather than through absorption and transpira- 

 tion. — Geo. D. Fuller. 



Taxonomic notes.— Cotton 10 has described collections of cryptogams 

 made by Mrs. Elinor Vallentin, in 1 909-1 911, on the western islands of 

 the Falklands. An interesting account of the phytogeography of the region 

 is followed by systematic lists of marine algae (138 spp.), freshwater algae 

 (54 spp.), lichens (95 spp.), and fungi (36 spp.). The representation of the 

 four groups of algae is as follows: Cyanophyceae, 4 spp.; Chlorophyceae, 

 26 spp. (one new); Phaeophyceae, 39 spp.; Rhodophyceae, 69 spp. (one new). 

 The list of fungi includes descriptions of 6 new species. 



Fernald and Weatherby" have investigated the perplexing genus 

 Puccinella T a group of species placed by some in Glycerin and by others in Fes- 



» Burns, G. P., The relative transpiration of white pine seedlings. Plant World 

 j8:i-6. 1915. 



» Cotton, A. D., Cryptogams from the Falkland Islands collected by Mrs. 

 Vallentin. Jour. Linn. Soc. Bot. 43:137-231- fis. 4-10. 1915. 



» Fernald, M. L., and Weatherby, C. A., The genus Puccinellia in Eastern 

 North America. Rhodora 18:1-28. pis. 114-117. 1916. 



