218 BOTANICAL INFORMATION. 



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Land $ a little knowledge of this kind will enable him to collect to 

 more advantage, and make fuller and more accurate notes of distribu- 

 tion, etc. 



VI. All possible means by which seeds are transported should be 

 observed : the stomachs of birds and fish, and the pellets disgorged 

 by hawks, owls, etc" examined ; the mud on the feet of swimming and 

 wading birds dissolved and searched ; the shaggy furs of animals, and 

 even the cleft hoofs of ruminants, are often agents of transport over 

 extensive areas.. During the season of migration of the animals, these 

 observations *hould be pursued with greater energy. 



VII. All indications of plants affecting waysides, the tracks of men 

 or animals, Indian encampments, etc., should be noted, and the effects 

 of clearing away forests, burning grass-land, etc., especially attended to. 



VIII. Great care should be taken so to ticket the specimens that in 

 case of any accident to the Collector, there may be no difficulty in de- 

 termining their localities, etc. If numbers, contractions, or private 

 marks are used on the tickets, these must always be accompanied with 

 the name of the district in which the plant was gathered, the date, 

 elevation (if above 2000 feet of the sea-level), etc. It is impossible to 



ive any general instructions as to the amount of information that should 



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accompany the specimens, but as a general rule it is recommended that 

 as far as possible the notes should be attached to the specimens to 

 which they refer. From neglect of this precaution many valuable col- 

 lections of plants and of observations have been rendered useless. 



IX. Thermometers and tubes will be supplied to the Expedition for 

 taking the temperatures of various bodies and of the soil at three feet 

 depth. It is very desirable that the temperature to which great heat 

 and cold penetrate the trunks of evergreen and deciduous trees, and 

 the soil near their roots, should be ascertained. 



In the case of trees, auger-holes should be bored obliquely to the 

 centre of the trunk, and two thermometers attached to a rod of wood 

 (one at the base and the other halfway up) inserted in the hole. The 

 thermometers should have both bulb and stem (except where the scale 

 must be visible) padded with cotton, and the auger-hole should be 

 loosely filled with sawdust, or other non-conducting material, and 

 plugged at the orifice. 



The temperature of the earth at three feet depth may be obtained 

 with sufficient accuracy for botanical purposes by sinking a brass tube 

 of that length in the exposed soil and placing in it a thermometer, 



