856 



POPULAR SCIENCE MONTHLY 



ical injury such as is produced in horses by 

 the hairs of crimson clover, or to the effect 

 of parasitic growths, such as ergot on rye. 

 Excluding all which operate in these ways, 

 there are, however, a large number of really 

 poisonous plants, the properties of which are 

 comparatively unknown. It is concerning 

 these that information has been sought by 

 the botanical division. Its report contains 

 descriptions of about forty plants, with fig- 

 ures, belonging to seventeen families. 



The I'nltcd States Biological Snrvey. — 



The Biological Survey of the United States 

 Department of Agriculture aims to define 

 and map the agricultural belts of the coun- 

 try in order to ascertain what products of 

 the soil can and what can not be grown suc- 

 cessfully in each, to guide the farmer in the 

 intelligent introduction of foreign crops, and 

 to point "out his friends and his enemies 

 among the native birds and animals. For 

 information on these subjects so important 

 to him the farmer has had to rely on his own 

 experiments or those of his neighbors, often 

 carried on at enormous cost to persons little 

 able to bear it. The- Survey and its prede- 

 cessor, the division of ornithology and mam- 

 mology, have had small parties in the field 

 traversing the public domain for the purpose 

 of studying the geographic distribution of 

 our native land animals and plants and map- 

 ping the boundaries of the areas they in- 

 habit. It was early learned that North 

 America is divisible into seven transconti- 

 nental belts or life zones and a much larger 

 number of minor areas or faunas, each char- 

 acterized by particular associations of ani- 

 mals and plants. The inference was natural 

 and has been verified that these same zones 

 and areas, up to the northern limit of profit- 

 able agriculture, are adapted to the needs of 

 particular kinds or varieties of cultivated 

 crops. The Survey is engaged in tracing as 

 precisely as possible the actual boundaries 

 of these belts and areas, and in finding out 

 and designating the varieties of crops best 

 adapted to each. In this undertaking it 

 aims to point out such exotic products as, 

 from their importance in other lands, are 

 likely to prove of value if introduced on fit 

 soils and under proper climatic conditions. 

 The importance of this work will be realized 

 when it is recollected that all the climatic 



life zones of the world, except the hottest 

 tropical, are represented in our country. 

 The colored maps prepared by the Survey 

 furnish the best guide the farmer can have 

 for judging what crops will be best adapted 

 for his particular region ; and in connection 

 with the work of the entomologist, show the 

 belts along which noxious insects are likely 

 to spread. The report of the Survey, pre- 

 pared under the direction of its chief, C. 

 Hart Merriam, though full of valuable infor- 

 mation not before presented consecutively, 

 is preliminary and only touches the edge of a 

 subject which is susceptible of copious elab- 

 oration, and is destined to be worked up with 

 immenseprofit. 



A Neolithie Lake Dwelling. — A crannog, 

 or lake dwelling, discovered in the summer 

 of 1898 on the banks of the Clyde, has re- 

 ceived much attention from English archasol- 

 ogists because of its unique situation on a 

 tidal stream, and of its being apparently 

 neolithic or far more ancient than any other 

 crannog yet examined, in all others the relics 

 being of the bronze age. Careful excavations 

 have been made in it and are still in progress, 

 and the refuse mound of the former settle- 

 ment has been sifted, with results that have 

 made it plain that there were design and 

 execution in the building, and that it was 

 occupied and inhabited for a long period. 

 Positive evidence of fire is afforded in the 

 shape of numerous firestones and calcined 

 embers, and indications of the condition of 

 life at the period are given by the implements, 

 ornaments, and tools recovered. The cran- 

 nog is about sixteen hundred yards east of 

 the Castle Rock of Dumbarton, and about 

 fifty yards from the river at low tide, but is 

 submerged when the tide is in to a depth of 

 from three to twelve feet, and is one hun- 

 dred and eighty-four feet in circuit. The 

 piles in the outer circle are of oak, which 

 below the mud surface is still quite fresh. 

 The transverse beams and pavement inside 

 are of wood of the consistence of cheese — 

 willow, alder, and oak — while the smaller 

 branches are of fir, birch, and hazel, with 

 bracken, moss, and chips. The stones in the 

 outer circle and along the causeway leading 

 to the dwelling place seem to have been set 

 in a methodical order, most of the bowlders 

 being about a lift for a man. The refuse 



