Till 
MICROSCOPICAL OBSERVATIONS. 
Mr. West noted the section (Fig. 1) as most interesting to him. The small size and lax character of 
the cellular tissues, the different conditions of the alkaloid salts in different portions of the bark, and the 
numerous prolongations of medullary rays in very pale tissue particularly arrested his attention ; but there is 
more even than appears at first sight, for by comparison with Fig. 6 of this same Plate it will he seen that, 
as to the size and shape of the cells, both these barks have put on the same appearance, which also corre- 
sponds in part to that of the richest Calisaya barks,* though not entirely confined to these. It is not so 
evident why this should so he, as it is that this lax cell-structure is favourable to the production of quinine. 
Fig. 2 shows this structure still more clearlv, together with the included alkaloids. 
Fig. 3 brings out the characteristic features of these rounded aggregations of crystalline matter from 
the same, drawn with the camera in situ , hut without the cells. 
Fig. 4 shows the whole section of bark under small magnifying power, giving the whole detail of 
structure, both of the old and new hark and their junction, which must be understood to he about x, the 
part to the left of which is renewed, whilst the portion to the right retains its normal appearance. 
Fig. 5 and Fig. 6 represent different ends of one and the same quill about 10 inches long sent to me 
by Mr. MTvor in the eighth remittance which I have previously described. About 2 inches of one end are 
labelled “ Chinchona crisp a, original bark under moss, 5 years old, 1868.” About 6 inches more remaining 
of the renewed end are labelled “ Chincliona crispa, renewed bark under moss 1 year old.” This though as 
thick, or even thicker than the unrenewed part, is distinguishable at first sight from the latter, and the point 
of junction is quite evident. The unrenewed part lias the appearance of the “ Colorada del Bey ” bark, but I 
have simply described it as C. officinalis, without defining the variety. The remarkable point in the 
microscopic section is the entire contrast in structure between the two ends of the same quill, a contrast 
which would surely cause these to rank as different species, if judged according to the rules laid down in the 
Anatomical Atlas of Dr. Berg ; I am not able to say whether an equal contrast prevails in the richness of 
the alkaloidal contents. The zone of liber fibres in Fig. 6 is very remarkable, as also the numerous and 
prolonged medullary rays, extending to the corky layer, and probably telling of rapid growth. 
Fig. 7 shows a section of the third crop of renewed bark under the curiously disturbing influence of 
the spiral tissue, which is seen in isolated portions as well as in bunches ; the pale colour of the adjacent 
portions is well represented, having the appearance of being subjected to the exhaustion of contents by 
the proximity of this spiral tissue. One spiral will be seen running a little within the corky layer and 
parallel to it, for a considerable distance. Towards the upper part of the figure we have lines of cells, 
and incipient medullary rays placed directly at right angles to those on which they abut. 
Fig. 8. With regard to the actual fact of different forms of spiral being present in the same section, 
this has been well noted by ITenfrey in the 1 Micrographic Dictionary,’ under the heading “ Spiral Struc- 
tures,” but it is not less interesting to add to the number of examples in which the fact has been recog- 
nized and carefully represented. 
* Berg’s ‘ Anatomischer Atlas/ Taf. xxx. ; Weddell, Histoire, tab. 1, f. 27, et alia inedita. 
