64 



SCIENCE. 



[Vol. XX. No. 495 



gant rate. Now meu trained in the knowledge of how plants 

 live and grow and behave have some basis on which they 

 can suggest ways of managing forests which will not only 

 yield all the timber that is needed at the present time, but 

 which will enable these forests to continue to yield such sup- 

 plies for an indefinite period of years. Forest management 

 is not unknown in other countries. We simply have trained 

 no men in this country to have any idea what forest man- 

 agement means. 



And then we have the immense subject of diseases of 

 plants, and that is a study which seems to have attracted the 

 greatest attention at the present day. The division of vege- 

 table pathology at the Department of Agriculture at Wash- 

 ington is receiving a vast deal more attention than the divi- 

 sion of forestry, and yet I doubt very much whether its 

 money value to the people is any greater. The money value 

 of the study of both these subjects to the American people, 

 and particularly to the farmers of the country, is almost 

 beyond calculation. We hardly realize what this money 

 value is. We are so used to losing a certain percentage of 

 our farm crops by diseases that we really pay no attention 

 to it. If our animals, our flocks and herds, should be deci- 

 mated as often as the crops are, we should hear such a hue 

 and cry as would bring immediate attention on all hands to 

 it. I suppose there is no one of you, who Vias given the 

 subject a moment's thought, but will agree with me that 

 the Joss from rust on the wheat crop for the present year, 

 stated in the very lowest possible terms, could not fall below 

 one per cent. How much money does that mean on six 

 hundred odd million bushels of wheat ? It means several 

 million more than has been laid out in the study of plants 

 in all the centuries. It means a great many hundreds of 

 thousands of dollars more than we shall lay out the next 

 century for the study of plants; and yet we are learning and 

 can learn how not only to check but how absolutely to pre- 

 vent such diseases as this. I do not say that this particular 

 one can be absolutely checked at the present time, but we 

 know ways in which it can be reduced to a minimum, even 

 at present. The same thing might be said in regard to such 

 diseases as those of the smut in corn and oats. Very careful 

 estimates of certain years have shown us that as much as ten 

 per cent sometimes of an oat crop is damaged by that one 

 disease alone. That might mean a good many millions of 

 dollars on that one crop. So that a study of these plant dis- 

 eases is by no means either fruitless or valueless. 



But you say, "Why not let anybody who is concerned 

 with these matters study them ? " Chiefly because it is not 

 possible for any man who does not know something of the 

 life history of the parasite which causes a disease to go about 

 checking or curing it. He may guess at some remedy, and 

 he may, by a lucky guess, hit upon the right remedy. He may 

 think of some process that possibly will turn out the right 

 one, but he is not nearly so apt to think about the right pro- 

 cess or to hit upon the right experiment as the man who has 

 been properly trained for this kind of work. That sort of 

 training means time to study, and tivie to work, and money 

 support while the work is being carried on. 



I might dwell at very much greater length on these vari- 

 ous topics ; but enough has been said, I hope, to give you some 

 idea of what modern botany is and what the modern botanist 

 is. It will at least give you a truer idea than you would 

 have if you considered him merely as the man who goes out 

 and gathers some plants, useful as this may be, or the man 

 who tears apart some flowers to find out what the names of 

 the flowers are. Rather, I would have you think of ihe 



botanists of the country as those men who are studying 

 means of discovering, checking, and curing the plant dis- 

 eases ; men who are studying how plants grow, and how they 

 may be helped in their growth and not harmed. They are 

 men who are studying what is the rational basis for our 

 modes of culture; and it is to these men the agriculturist 

 must turn, with the hope that their experiments will lead 

 him in the future, as they have in the past, to more rational 

 modes of cultivation, and to better knowledge of the organ- 

 isms, the very intricate organisms in spite of their simplicity, 

 with which he has constantly to deal. 



NOTES ON A DESTRUCTIVE FOREST TREE 

 SCOLYTID. 



BT ANDREW D. HOPKINS. 



The family of beetles known as Scolytidse contains in this 

 country, so far as known, something over 160 species. They 

 are small, cylindrical, brown or black beetles. The largest 

 one of the family, Dendroctonus terebrans, is thirty-two hun- 

 dredths of an inch long, while the smallest, Cripturgus 

 atomus, is but four hundredths of an inch long. With a 

 few exceptions, beetles belonging to this family breed in the 

 bark of wood of ditlerent forest and fruit trees. Each 

 species usually has a preference for certain kinds of trees. 

 Those feeding on the bark are called bark beetles, while 

 those entering the wood are termed timber beetles. The 

 bark beetles breed in and feed upon the inner bark of trees 

 or logs, and when fully developed emerge through the bark, 

 leaving it pierced with small round holes. The timber beetles 

 enter directly through the bark, making their "pin-hole" 

 tunnels in all directions through the wood; their eggs are 

 deposited in these tunnels, and when the young are fully 

 developed they emerge from the original entrance made by 

 the parent beetle. 



It has been claimed that Scolytids never attack healthy, 

 living trees. We acknowledge that as a rule the difTerent 

 species of this family have a preference for unhealthy trees 

 or those which have been broken by storm or felled by the 

 axe, but in this Dendroctonus frontalis we certainly have 

 an exception to the rule. From the abundant evidence I 

 have obtained during extended and careful investigation, I 

 am convinced that the deaths of large and small, vigorous 

 trees of five species of pine and of the black spruce was 

 caused primarily by the attack of this insect; in fact, this 

 species seems to have a preference for the green bark on the 

 living pine and spruce which they invade. 



As Entomologist of this Station, I have conducted some 

 investigations regarding the ravages of this beetle, and, since 

 May 3 of this year, have travelled about 340 miles through 

 some of the principal regions of the State, where the pine 

 and spruce are most common. The species of pine observed 

 were the White Pine {Pinus alba), the Yellow Pine (P. 

 echinata), the Pitch Pine (P. rigida), the Table Mountain 

 Pine (P. pungens), and the common Scrub Pine (P. inops). 

 The Black Spruce (Picea Mariana) is also a common and 

 valuable tree on some 500,000 acres of the higher mountains 

 and table-lands of this State. 



Trees varying from five inches in diameter to the largest, 

 finest specimens of the five species of pine mentioned, and of 

 the Black Spruce, were found dying in different sections 

 from a cause which it was my duty to investigate. A large 

 number of the dead, dying, and green trees were felled and 

 examined. Every part of the trees from the roots near the 

 surface to the terminal twigs and leaves was carefully 



