1 68 The Scottish Naitiralist. 



followed by a blue reaction especially in the upper % of the 

 thalamium. In a very short time thereafter the thecae are seen 

 to assume a beautiful and deep vinous red colour. On the 

 application of more of the solution, those parts of the thalamium 

 immediately adjoining the thecse are also seen to assume the 

 same vinous red tint, and on the whole being saturated, a thin 

 section reveals the vinous red tint throughout. Now, as a strong 

 element in specific distinction is being founded on the differ 

 ences between the reactions of the general thalamium and 

 thecae proper, at what stage of the process detailed above 

 ought observation to stop? It is clear, that had a stronger 

 solution of Iodine been used than that commonly recommended 

 the last phase of the reaction would have appeared almost im- 

 mediately after the first. As this is merely the first of a series 

 of observations on the use of chemical re-agents, in the discrimi- 

 nation of species of Hchens, I shall defer to another opportunity 

 what I have to say further on the subject. 



SCOTTISH GALLS. 



By JAMES W. H. TRAIL, M.B., F.L.S. 



DURING th-e past month I have found a few galls not 

 previously known to me, descriptions of which I sub- 

 join. I may add that I should be glad of any help towards 

 adding to our knowledge of galls in Scotland ; from many, in 

 fact from most parts of the country, our information about these 

 productions is very scanty or is entirely wanting. 



Thlaspi arvense L. — The galls consist of rounded swellings 

 projecting from one side of the root just below the base of 

 the stem ; they usually include more than half the circum- 

 ference of the stem, and may reach ]/^ inch in diameter. 

 Externally they resemble the root ; internally they are 

 found to be composed of rather hard tissue, enclosing a 

 cavity varying in size according to the development of the 

 larva. I have not succeeded in rearing the gall-maker, 

 but I have litttle doubt that it is a species of weevil 

 ( CcuthoHiy fichus). (Called plants were abundant in July in 

 a field near Old Aberdeen. 



Lotus major L. — The galls on this plant resemble those of 

 Cecido7nyia Loti De Geer on Lotus corniculatus, and are 

 most probably the work of the same insect. One or more 



