1880. 



AND HORTICULTURIST. 



85 



and the lobes generally, though not always, end 1 dwarf form of the American is C. Ksempferi. 



in a sharp acute point. The seed pods are very There is no mystery about it that we see— Ed. 



distinct, being remarkably slender, though of 



about the usual length, only about the size of a 



goose-quill. Seeds also quite small ; one pound 



containing 50,000, while a pound of the common 



only go a little over 20,000. 



'• Several to whom I have sent it incline to call 

 it Ka;mpferi, but it is very unlike what we have 

 for Kfempferi, from Rochester, and which I 



G. M.] 



THE PEAR LEAF-MITE. 



BY MR. THOMAS TAYLOR, 

 MICROSCOPIST TO THE DEPARTMENT OF AGRICUL- 

 TURE, WASHIXGT(JN, D. C. 



In your magazine recently, page 18, Prof. T. 

 J. Burrill, of Champaign, Illinois, is credited as 

 think correct. Plants ten years old, nine and a being the first person in this country to discover 

 half feet high, and forty feet in circumference of the cause of what is known as pear-leaf blister, 

 branches at four or five feet from the ground; in- In his article on that subject quoted in your 

 numerable stems like a great old currant bush, magazine. Prof. Burrill says: "A wide-spread 

 Top dense, almost even, and smooth as a clipped disease of pear leaves in this country and in Eu- 



hedge, though never cut; leaves small, dark 

 green and glossy ; twigs slender. No bloom 



rope, is caused by a mite, to which Scheuten, a 

 German naturalist, gave the name of Typhi o- 



yet, though have watched carefully for several : dromus pyri. This was twenty-one years ago. 

 years. I think it will be nice worked standard Ignorant of this information the writer during 

 high, but for timber, might as well plant goose- ' the last season, 1879, rediscovered the cause of 

 berry bushes. Some one suggest that our this disease, and, it is believed, first announced 

 Kajmpferi may be Bungei, but I think that is its occurrence in this country." 

 still more dwarf,— stouter in its twigs." The following extract from the Annual Report 



At another time Mr. Teas sent me some of the Department of Agriculture for the year 

 small trees of speciosa, Japan and Bungei, as 1872, page 113, will clearly demonstrate that I 

 he has them, and wrote regarding them. made the discovery Prof. Burrill claims as early 



••It (the Japan) probably belongs to the | as May, 1872 : 

 Ksempferi section, but is altogether distinct from j "■ Mites in Pear-leaves.— In May many leaves 

 K. itself. I have no Keempferi, but enclose a of the pear tree were observed to be covered 

 few seeds which I suppose to be K. I bought with dark-brown blotches somewhat like a fun- 

 it in France for Bungei, and what I now send ! gold growth, but upon examination by Mr. Tay- 

 you as B. I bought at Rochester as K." ! lor, microscopist of the Department, these 



Now Mr. Editor, the more we study this ques- blotches were found to be inhabited by small 

 tiou the less we seem to know about the identity mites almost invisible to the naked eye. These 



of kinds. Is this Japan catalpa of Mr. Teas 

 Bungei or some new kind? And is the dwarf 

 one C. KiBmpferi? 



mites appear to run all over the leaves, but es- 

 pecially to burrow in the brown patches, which 

 appear to be entirely eaten out by them. Their 

 are 



An answer will remove a good deal of confu- bodies are long, cylindrical, yellowish-white, 

 siou at present existing, regarding the proper with only two pairs of legs, placed very far for- 

 names of these diflerent species. ward near the head, and they move with consid- 



[We have received this since the note in our | erable agility. They are also marked with a 

 '^ Forestry" department went to press. We [ multitude of rings, and have two long hairs or 

 would simply suggest to our friend that when i bristles and two shorter ones on the end of the 

 *'the more we study the less we know," it ought abdomen. There is a somewhat similar mite nien- 

 to indicate that we have been studying in the tioned by Packard as the Typhlodromus pyri, of 

 wrong direction. The best direction to study a Scheuten, which is said to live under the epider- 

 botanlcal question, is in the line of botanical mis of pear leaves in Europe, but no mention is 

 authorities. Probably the best authority on this ! made of the brown blotches on the leaf, appa- 

 Catalpa question is DeCandolle, as already i rently formed by the mite. In his figure also 

 stated. If DeCandolle is wrong, the error has I the head is much more obtuse than those exam- 

 not been pointed out by any botanist that we ; ined in the Department. A thorough drenching 

 know of; and we must wait till some one of with whale-oil soap-suds would doubtless destroy 

 them does. In the mean time the lobed leaved many of them, as their bodies appear to be very 

 kind with flowers remains C. Bungei, and the : soft. All infested leaves, likewise, should be 



