Exhibitions. 
Dr. Balfour exhibited from Messrs. Lawson, a fine. cone of Pinus 
Sabiniana; also, under the microscope, specimens of porous and true 
punctated tissue in coal: and he noticed the formation of coal by Si- 
gillarias, and the presence of scalariform tissue in such coal. 
Mr. M‘Nab exhibited various cut roots of trees which had been 
transplanted by Mr. M‘Glashen’s patent apparatus a year ago, and 
which showed tufts of fibrils varying from 7 or 8 inches to 18 inches 
in length, produced from the cut extremities. 
Dr. Balfour remarked, that Mr. M‘Glashen’s plan of transplanting 
had been very successful; and he stated that the cutting of the 
roots did not appear to operate in arresting the growth, and that the 
objection urged by some, that the plants, in place of producing 
wood, were likely, in such circumstances, to exhaust their energies 
in the production of flowers and fruit, had not been verified by the 
results so far as already observed. The plan of at once transplant- 
ing the trees after their roots were cut, and allowing them to form 
young rootlets in their permanent position, seemed preferable to the 
plan of cutting the roots the previous season by trenches to induce 
the formation of roots, and then running the risk of injuring these by 
the after removal. 
My. Evans exhibited Tasmannia aromatica, in flower, from the 
Experimental Garden. 
The following papers were read :— 
Pollen of Zamia horrida. 
‘On the Pollen of Zamia horrida.”. By Dr. Balfour. Dr. Balfour 
drew the attention of the Society to the pollen of some of the Cyca- 
dacez, more especially that of Zamia horrida. The pollen he stated 
to be, in its ordinary condition, elliptical, with a groove in one side, 
and to resemble very much a grain of wheat in appearance. The 
groove is formed by the folding inwards of the edges of the pollen- 
grain, which, when fully expanded under the action of water, becomes 
completely spherical. When water is applied under the microscope 
to the elliptical pollen-grains of Zamia, the two edges of the groove 
are seen to unfold and spread out so as to produce the circular grain ; 
when allowed to dry, the grain resumes the elliptical grooved condition. 
It is perhaps difficult to say whether the elliptical or the spherical 
