108 Proceedings of the Royal Society 
sometimes occurs loose in cavities, two of which were found with 
a considerable loose lining of it. 
Nothing has been found on the exterior of these fossils distinctly 
or even probably referable to the bark of the original trees. This 
deficiency is explicable, if, as various circumstances seem to indicate, 
the trees did not grow where they lie, but have been water-borne, 
so that their bark, like their roots and branches, had been worn 
away. The outer crust of coal has been thought to represent the 
bark in such fossils, but that cannot be here; for, in the first 
place, it covers large surfaces of the trunk of No. 5, which are 
evidently the places from which lost branches had sprung ; and, 
secondly, which is more to the point, it' uniformly covers the blunt, 
rugged point, and the complete circuit, of the split sector, which 
was supposed erroneously by the quarrymen to be a branch entire 
in its whole circumference, and over the greater part of which it is 
impossible that there could have been any bark. It is difficult 
to say how this crust was formed. It is also a very difficult question 
to settle, how the carbon of this exterior crust was converted into 
coal, and that of the interior into charcoal. But further examina- 
tion of such fossils may supply the answer, and throw some light 
on the process of formation of coal in general. 
2. On the Formation of Buds and Boots by the Leaves 
of the Ipecacuan Plant ( Gephaelis Ipecacuanha ). By 
Professor Balfour. 
The rapid propagation of Ipecacuan in India is an object of 
importance, and as such has occupied the attention of the Indian 
Gfovernment. The Edinburgh Botanic Garden has contributed 
largely to the stock of Ipecacuan plants now in cultivation in India. 
The plan of sending cuttings of the roots or rather rhizomes 
enveloped in moss has been very successful. We have been able 
in 1873 to send these cuttings in small boxes through the post. 
Dr Henderson, the present interim Director of the Botanic Garden 
at Calcutta, reports most favourably of this plan. He carried out to 
Calcutta in 1872 small boxes 8 inches by 2, containing germinating 
rhizomes of Ipecacuan, and roots of Jalap. These are now thriving 
under his charge. This mode of transmission will save much 
