SECRETARY'S PORTFOLIO. 527 



plant, or, if it does, it is not supplied at the proper time. It may be that 

 there is a difference of structure so that the rust plant does not as readily 

 enter one as another. 



Peak and Cheery Slugs. — Mr. C. F. Burroughs, president of the Benzie 

 County Horticultural Society, answers a number of queries concerning the 

 pear and cherry slug by relating his own experience the past season. He 

 says: 



At the usual time for them to appear, I found all my cherry and pear trees 

 entirely covered with the slugs, being as many as three and five on a single 

 leaf. I treated them as we always have, and with perfect success. I took 

 one pint of soft soap to one pail of soft water and showered the trees 

 thoroughly; the next day I found in looking over the trees that only about 

 one quarter as many were to be seen, and a day or two later many dead slugs 

 were on the leaves, while many more had disappeared to parts unknown ; in 

 one week there were still some slugs to be seen on the trees, and I showered 

 them once more, as before, and in a few days they were all gone, and none 

 have been on the trees since. 



Last year our apple trees were badly overtaken with the green aphis, and 

 I showered them with the same solution, and only one showering, with per- 

 fect success, not one aphis having made its appearance since. 



Now with those who have never used this solution for slugs, bark lice and 

 aphis, its usefulness may be doubted, but with us, it is practical. Father 

 has used this for all three of these insects for a good many years. 



Pyrethrum. — Prof. A. J. Cook furnishes the following notes upon the use 

 of Pyrethrum : 



The character and use of pyrethrum, though pretty well understood by our 

 intelligent horticulturists, is not, I believe, as well known and appreciated as 

 its merits deserve. 



The powder sold under the several names, pyrethrum, buhach, Persian insect 

 powder, and Dalmatian insect powder, is simply the pulverized flowers and 

 stems of two or three plants belonging to the genus pyrethrum. The powder 

 from any of the species, P. roseum, P. corneum, or P. cineraria-folium, is valu- 

 able, though that from the last named has been said by some to be the best. 

 These plants are natives of Persia in Asia, and dalmatia in Europe, hence the 

 names Persian and Dalmatian powder. Now they are grown extensively in Cali- 

 fornia, where the name Buhach has been chosen as a sort of trade mark. 



This powder, which has been proved to be an excellent insecticide, is non- 

 poisonous to vertebrate animals, even though eaten; while to many insects it is 

 very destructive, though it paralyzes or kills tnem simply by contact, and not 

 by being taken as food. The active principle seems volatile, and so, old pow- 

 der, especially when not kept closely confined in air-tight vessels, is apt to be 

 partially or wholly worthless. 



Pyrethrum seems to be most effective to destroy the higher insects. Thus 

 most hymenoptera (bees, wasps, ants, sow-flies, etc.). diptera (two-winged flies), 

 and many coleoptera (beetles), and some hemiptera (bugs), especially the plant 

 and parasitic lice, are very susceptible to this insecticide. I have found that 

 some beetles and many bugs are little affected by the use of this powder. 



Pyrethrum may be applied by mixing with water, or as a powder. In the 



