BOTANY. 921 



consist mainly of Festuca rubra, F. ovina, Agrostis vulgaris, Poa pra- 

 tensis, P. cassia, Anthoxanthum odoratum, Aira ccespitosa, and Alopecurus 

 geniculatus. Trifolium repens and Alopecurus genieulatus occur in moist 

 places. AchillcBa millefolium is quite abundant on the meadows, and 

 a large number of other plants, especially sedges and the coarser 

 grasses, are frequently found in small quantities. Other plants fre- 

 quently found on the meadows are Carex vulgaris, G. cryptocarpa, G. 

 chordorhiza, G. rariflora, G. ampullacea, G. limosa, C. dioica, C. eanescens, 

 Menyanthes trifoliata, JEriophorum angustifolium, E. capitatum, Juncus 

 triglumis, Scirpus ccespitosus, Vaccinium uliginosum and Betula nana. 

 "Iceland is the laud of the Cyperacese and the coarsest species of 

 grasses, but cattle which through generations have become accustomed 

 to the coarse food do well on it." — f. w. woll. 



The seeds and seedlings of some Amentiferee, W. W. Rowleb 

 and G. T. Hastings (Proc. Amer. Assoc. Adv. Sci., 47 (1898), p. 436).— 

 The authors state that compared with other groups, the seeds and 

 seedlings of this group have not been observed to any extent. This 

 fact led them to a series of studies, and their conclusions, briefly stated, 

 are as follows: In the walnuts and hickory nuts the cotyledons cor- 

 respond to the valves of the nut and are deeply two-lobed. The 

 divisions of the embryo resembling cotyledons are each made up of 

 valves of the cotyledons. The seeds of hickory will germinate without 

 frost action, while those of walnut require it. The taproot of all these 

 seedlings is very thick in young plants and very long in older ones. In 

 the case of chestnuts and oaks the shell is spilt by swelling of the coty- 

 ledons in germination. In the species of oak studied the leaves of the 

 seedlings were very much alike, being neither very deeply cut nor 

 lobed. The beech is said to be the only one of all the genera examined 

 in which the hypoeotyl lengthens or the cotyledons become aerial. 



Temperature of plants, F. Schleichert (Naturw. Wchnschr., 13 

 (1898), pp. 409-472 ; abs. in Jour. Roy. Micros. Soc. [London], 1899, No. 

 1, p. 57). — Observations on the temperature of trunks and leaves are 

 reported, from which it appears that the temperature of the interior of 

 the trunk of Pavia rubra at a depth of 12 cm. below the surface was 

 dependent on the temperature of the surrounding air, attaining its 

 maximum and minimum later than that of the atmosphere. It is 

 influenced to a less extent by the temperature of the soil and of ascend- 

 ing currents of water, as well as by the degree to which the leaves are 

 exposed to direct sunlight. The temperature of leaves was found in 

 some cases to be slightly lower (0.7° C.) than that of the surrounding- 

 air, owing to transpiration. In other cases, such as thick-leaved plants 

 of aloes and cactus, when exposed to bright sunlight the temperature 

 was considerably higher; when the air temperature was 20° that of the 

 interior of the leaf was 28.5° 0. This difference is said not to be due 

 to the development of heat in the leaf, but to the absorption of heat 

 through the thick mass of leaf or stem. 



