44 
PROGRESS OF MICROSCOPICAL SCIENCE. 
power, any essential difference between the egg of man and those of 
most of the higher mammals, and states that the pictures showing the 
identity of mammalian embryos in plate v. of Haeckel’s Anthropo- 
genic differ essentially from the reality, and, finally, that the figures 
of apes’ faces given by Haeckel on his title-page show a great agree- 
ment existing between the features of apes and of the lower human 
races, but that this resemblance does not appear in photographs.” 
On the Porosity of Wood . — Professor Sachs has published a pre- 
liminary communication in regard to the porosity of wood, which 
contains notes of many interesting experiments. One of these is the 
following, which is of interest. The best grade of artist’s vermilion 
was treated with a large quantity of distilled water and repeatedly 
filtered through filter paper. The pigment was now left in so fine a 
state that it exhibited the well-known Brownian movement. Fresh 
cylinders of wood three to four cm. long, cut from a living stem of a 
conifer, were fastened to the lower end of a glass tube which at the 
upper part communicated with a broad vessel ; tube and vessel were 
filled with the pigment emulsion so that the wood was under a constant 
hydrostatic pressure of 160 cm. Even at the end of three days the 
water which filtered through was perfectly clear and contained no 
trace of the vermilion. The upper transverse sections of the cylinders 
showed that all the layers of the spring-wood were bright red, the 
autumn layers were not red at all, or at most only in radial stripes, 
the heart-wood was wholly uncoloured. On splitting the cylinder of 
wood, the vermilion was seen to have penetrated nowhere deeper than 
two to three millimeters, corresponding to the length of the cells in 
the wood employed ; the rest of the wood was colourless. The 
microscope shows that the majority of the spring-wood cells are 
wholly filled with vermilion even to their lower tips ; also that the 
bordered pits of these cells are thickly filled with vermilion, and 
sometimes this did not pass through into the neighbouring cells which 
seemed to be in communication with them ; there was obviously an 
obstruction in the bordered pits themselves. This is interpreted as 
showing that there still remains in the discoid markings a thin 
membrane as claimed by Hartig. The autumn-wood cells appeared 
to take up very little vermilion, and the medullary rays none. 
Microscopical Preparations of Fungi . — A recent number of 
‘ Grevillea ’ contains the following notice, which may be of interest 
to some of our readers. “ For many years the want has been widely 
felt of some one with a practical knowledge of fungi, and withal 
expert in their manipulation, who could prepare for those who were 
unable to do it for themselves, mycological slides. We have often 
been applied to during the past to indicate such a person, if he could 
be found, and the application has been fruitless. This, however, is no 
longer the case, for we have had the opportunity of examining some of 
the microscopical preparations of fungi which have been produced by 
the Rev. J. E. Vize, of Forden Vicarage, Welshpool, and do not 
hesitate to recommend them to any of our readers who may be in 
search of such aids to study. It may be observed that no small 
