U4 



The Scottish Naturalist 



ON THE ARTIFICIAL PRODUCTION OF DOUBLE FLOWERS 

 'AND OF OTHER ABNORMALITIES OF STRUCTURE. 



By Dr. J. Peyritsch. 



[The subjoined paper by Dr. Peyritsch, the well-known investig- 

 ator of the causes that give rise to abnormal structures in 

 plants, was published in the beginning of the present year in 

 the Sitzungsberichte der kaiserlichen Akademie der Wissensch- 

 aften in Vienna, in Vol. XCVII., pp. 597-605. As it is 

 scarcely likely that the readers of the Scottish Naturalist are 

 familiar with the paper in the original language, and as the 

 statements in it are of very great interest, with regard to the 

 influence of mites on plants, we believe that our readers will 

 consider that we have done well in placing a translation of it 

 within their reach. It is very desirable that the suggestive 

 records in it should stimulate to researches of a similar nature, 

 with respect to the influence of gall-mites, on the plants of the 

 British Islands. This method of investigation, in Dr. 

 Peyritsch's hands at least, appears to be full of promise. — Ed., 

 Scot. Nat.} 



J N the subjoined paper are set forth the results of my experi- 

 mental researches upon the causation of abnormalities of 

 structure, which have been carried on during several years. I 

 have been successful, by means Of a simple and readily applicable 

 procedure, in producing on a number of plants either abnormal leaf- 

 forms or double and proliferous flowers. 



The plants on which the observations were made belonged, for 

 the most part, to the Valerianacea and the Cruciferce ; but one or 

 more species of the Scrop/iu/ariacece, Conunelynaceaz, and other 

 orders were also subjected to the procedure. The result was 

 striking in Valerianaceaz and in Cruciferce. 



Of Valerianaceaz the method was tried on Valeriana alliarice- 

 folia, celtica, dioica, elongata, globularifolia, montana, officinalis, Phu, 

 saliunca, saxatilis, supina, tuber osa, Valerianella olitoria, Szovitsi- 

 ana, vesicaria, Fedia Cornucopia, Centranthus Calcitrapa, inacro- 

 sifhon, ruber, and Patrinia rupestris. 



Abnormal leaf-forms appeared upon Valeriana alliarhsfolia, 

 celtica, dioica, elongata, montana, officinalis, saxatilis, supina, trip- 



