330 S. Reginald Price. 
was sparing in quantity, was eventually obtained from small shallow 
patches of sand away from the dunes themselves; in these the 
growth in length of the roots was limited, and it was possible by 
careful digging to obtain the apices at no great distance from the 
shoots. 
Methods. 
Anatomical investigation was difficult on account of the particles 
of sand forming the sheath and adhering to the outer surface of the 
roots. The outer layers of sand were easily disposed of, and in 
most cases had become removed in the processes of collection and 
transport. Many of the particles adhered firmly, however, so that 
section cutting was practically impossible without special treatment. 
The root-tips themselves were comparatively free from sand 
except for some very small particles. Attempts were made to clean 
these by brushing gently with a soft “ camel’s-hair ” brush and after 
this treatment they were embedded in paraffin and sections were 
cut with a Cambridge Rocking Microtome in the usual manner. A 
few fairly good sections were obtained, but in most cases small 
particles of sand still remained which tore the sections. For the 
thicker parts of the roots, where the sandy sheath was fully developed, 
brushing was quite useless. 
Silica is dissolved by the action of hydrofluoric acid, and use 
was made of this reaction. The pieces of root were placed in 95% 
alcohol and were treated with commercial hydrofluoric acid which 
was added from time to time. 1 Glass vessels coated with paraffin 
wax were employed. 2 The pieces when they appeared free from 
sand were transferred to fresh alcohol and then treated as usual, 
With the older portions of the root this method was quite successful, 
and following its use, good sections could be cut, showing the 
structure of root-hairs, and so on. For the root-tips the treatment 
was usually too severe. Unless very dilute acid he used, the outer 
portions, including the root-cap and secretory layer, are more or less 
completely disintegrated and removed. Using weak acid some 
sections were ultimately obtained, but the tissues were rather 
softened and often displaced, though good sections of the secretory 
layer ( v . infra) were produced. 
With regard to stains, Diamant Fuchsin was good for the muci¬ 
lage, and was followed by a very dilute alcoholic solution of Licht- 
1 The fumes of the acid are extremely dangerous and the greatest 
precautions must be taken when using this method. In all 
cases above the reactions were performed in the open air. 
2 Bolles Lee, A. The Microtomist’s Vade Meeum, 4th edition, 
London, 1896, pp. 327-8. See also Zool. Anz. 97, p.593, 1881. 
