The Scottish Naturalist. 19 



usually empty, but not otherwise distinguishable from those 

 below, and the gall is chiefly made up of a mass of thin-walled 

 cells packed full of granular contents. In each cell is a strongly 

 refracting nucleus, in which lies a distinct nucleolus. The 

 layers of thick -walled cells have disappeared, but the fibro- 

 vascular bundle is represented by cells smaller than those of the 

 cortex. There is no distinct line of demarcation between the 

 cortex and the central tissues, hence it is difficult to determine 

 which has undergone the greater abnormal growth, but the 

 cortex seems to be the less changed of the two. In the interior 

 of the gall live the makers of it, as in A. alba; they are Anguil- 

 lula, and belong to the genus Tylenchus, though of this I am 

 not certain in the absence of males. In the small galls only 

 one or two of the worms are to be found ; but in the larger 

 galls, in October, a multitude of eggs and of newly -hatched 

 embryos are present, with an occasional adult female. The 

 eggs are oval, with blunt ends, about xoVo x tijoo mcn m size i 

 and are so transparent as permit a full examination of the 

 embryo within, which is three or four times as long as the 

 egg. The immature worms, examined by me in October, were 

 fiMJo- Wo x o 3 inch? and the adult females were about itNjJ inch. 

 The Anguillulce from both this and the former gall are able to 

 endure desiccation without being killed ; but I have not had an 

 opportunity as yet of testing this power for any long period of 

 time. Galls of Anguillulce on the roots of Elymus ai'enarius 

 have been found in Denmark by Dr E. Warming (' Bot. Tids.,' 

 3d series, vol. ii., 1879); an< ^ root-galls formed by these creatures 

 have also been found on Poa annua, on Triticum repens, on 

 7cheat, on barley, and on oats, but I am not aware that they 

 have yet been met with on these plants in Scotland. 



In the ' Scottish Naturalist,' vol. iv. p. 206, I gave references 

 to mite-galls, described and figured as fungi, under the generic 

 name Erineiwi, by Greville, in the 'Edinburgh Philosophical 

 Journal.' I have since had access to two works by Greville, — 

 the 'Flora Edinensis,' published in 1824, and the 'Scottish 

 Cryptogamic Botany,' published in 1823-28. In the former are 

 described, and in the latter are described and figured, the fol- 

 lowing mite galls, under the name Erineum. 



1. E. clandestinum, Grev. — E. oxyacantha, Pers., on haw- 

 thorn-leaves ('Sc. Nat.,' iv. p. 14). 'Fl. Edin.,' p. 450; ' Sc. 

 Cr. Fl.,' vol. iii. t. 141, f 2. 



