II April. 1910.] Potatoes and Tomatoes on the Same Plant. 205 



" Witches' brooms," common in the old land on birch trees, are reallv 

 caused by one of these gall-mites. Another known as the currant gall-mite 

 is more or less frequent on currant bushes in Great Britain and elsewhere. 

 Still another variety forms galls on plum twigs in American orchards 

 We are all familiar with the Blister gall-mite of the pear {Phyto-ptus -pyri), 

 or at least familiar with the appearance of the leaves attacked. An excel- 

 lent description, with coloured plate, may be consulted in Mr. French's 

 Handbook of the Destructive Insects of Victoria, Part I. 



Another parasite that has special interest to us is the Rust-mite 

 {Phytoftus oleivorus), which punctures the oil cells and causes the appear- 

 ance popularly known as " Maori " on oranges. This name is doubtless due 

 to the discolorations or markings on the rind being fancifully compared to 

 the tattoo marks on the Maori skin. 



The acarian that causes Erinose of the vine is known as Phytoftus 

 {Eriofhyes) vitis. In countries where it is common it is not now regarded 

 with much concern. Sulphur dressings during the vegetative season usuallv 

 keep it down as readily as is the case with red spider. When the invasion 

 is more than ordinarily severe, treating the vine stocks during the dormant 

 season with kerosene emulsion, or any insecticide, or even with hot water, 

 "has proved efficacious in ridding the vineyard of this by no means for- 

 midable invader. While it will be wise to destroy them, and prevent their 

 further distribution, yet their presence need give no cause for unnecessary 

 alarm. 



POTATOES AND TOMATOES ON THE SAME PLANT. 



D. Mc Alpine, Vegetable Pathologist. 



In the article on " Irish Blight in Tomatoes " which appeared in the 

 Januarv number of the Journal, it was stated, as showing the close relation- 

 ship existing L>etween potatoes and tomatoes, that a tomato plant could be 

 grafted on to a potato plant, w^ith the result that both tubers and fruits 

 would be produced. This is a well-known fact, although I have not carried out 

 the experiment myself, but a clear photograph of such a plant has recentl\ 

 appeared in the Deutsche Landivirthschaftliche Presse of December, 1910, 

 for a copy of which I am indebted to Mr. Percy Wilkinson, Commonwealth 

 Analyst. The accompanying illustration shows the potatoes below and the 

 tomatoes above, and the historv of this plant mav here be given as recorded 

 by Dr. Karl Snell. 



Potatoes were planted in pots on ist June, and on 19th June one of the 

 young potato haulms which had developed three shoots was cut across 

 and each of the shoots had a young tomato nlant grafted on to it. The 

 grafting was done in the usual manner bv cleft-grafting. On 4th July, 

 the plants were removed from the pots and planted out in the garden 

 where they remained until they ripened. The photograph shows one of 

 the plants as it appeared at the end of October, bearing 18 tomatoes and 

 II potatoes. 



From the illustration it may be seen that the foliage was almost 

 exclusively that of the tomato and the.se leaves supplied the nourishment, 

 not onlv for the tomato, but also for the potato. Thus, from the same 

 nutritive material, two quite different parts of different plants were 



