demy, observes, with reference to M. Schoenbein's views,—1st. That blue is not the only colour which the Boleti assume; 2ndly. He asks, Why does not the change of colour take place spontaneously in the plant itself, since all the elements which produce the phenomenon are produced by the plant? 3rdly. How is it that simple pressure often produces the same effect as rupture? And, 4thly, Why do not all Boleti change colour in the same manner? Mons. Kiekz suggests a scheme of inquiry with the view of more fully determining the question.[1] He considers that, before the point can be looked upon as settled, it will be necessary that the anatomical structure and chemical composition of the Boleti which change colour, should be examined and compared with the structure of those which do not change, and that this comparison should be made at different periods of the growth of each species; that care must be taken to observe the difference of colour of the flesh of the pileus and of the hymenium in the same species, and to ascertain in which organs the colouring matter resides; that inquiry must be made whether similar colouring matter exists in other Fungi in which similar changes have been observed, and whether any relation subsists between the change of colour which takes place in the Boleti and that which has been observed to occur in the milk of certain Lactarii. This inquiry is, doubtless, sufficiently extensive: if any mycologist should be willing to undertake it, we believe the prize of the Belgian Academy is still open. It has been suggested that the colouring matter consists of aniline, and this idea has been brought forward again in the "Comptes Rendus" (16th July,1860(, where M. Phipson remarks:—
"The colouring matter which exists in these Boleti in a colourless state is soluble In alcohol, not easily miscible with water, and becomes resinous in the atmosphere. It possesses the properties of aniline, and, under the action of oxydizing agents, produces the same colours as aniline and its saline compounds."
M. Martens[2] has objected that the matter is not likely to be ani- line, because aniline, he says, has not been found in any vegetable, forgetting apparently that it exists largely in Indigo.
Amongst the different divisions of Fungi, of which a concise general account is given in the work before us, reference is made to a very remarkable group (the Myxogastres), to which considerable biological interest attaches—an interest, moreover, in which the zoologist and the botanist are equally concerned. The peculiarities of the group are very great, as will be seen by the following extract:—
