Growth Changes in the Mined Leaf Mine and Gall

Abstract

Attention has already repeatedly been drawn to the fact that the connections between the mining parasite and the infested leaf are particularly close. When discussing the colour and discolouration of the mine and the surrounding parts of the leaf, we noticed a connection between the two and saw that the plant reacted to the attack of the parasite. We shall now find that inside the leaf along the mine channel, much further reaching changes take place, accompanied by deviations in the growth of the plant, which are quite unknown in a normal leaf. Striking analogies occur in such cases with the growth abnormalities which were discovered in the investigation of plant galls; it can be shown that we are now entering a border region between the study of mines and galls, which appears particularly suitable for focussing attention on the development of gall producing habits and showing how this at least partially has been derived from mining. These changes are in many cases apparent externally, in others they can be detected by a microscopical examination of the histology of the mined leaf; in many cases the two go together, with the external signs indicating that changes have also taken place inside the leaf.

The online version of the original chapter can be found at http://dx.doi.org/10.1007/978-94-015-7196-8_36