62; VAN TIEGHEM AND LE MONNIER. 



of the spore, being still covered with the exospore and filled 

 with fusiform nodules. 



We do not think it necessary to describe in detail the 

 structure of the sporangium, the development and dispersion 

 of the spores, or the mode of elongation of the sporangiferous 

 hypha ; these phenomena take place exactly as in Mucor, 

 and Carnoy has fully described them. We will merely remark 

 that the membrane of the sporangiferous hypha does not 

 become incrusted with granules of calcium oxalate, and that 

 it becomes gradually coloured from below upwards, before 

 the formation of the sporangium, in a very remarkable 

 manner, which is in singular contrast with the golden-yellow 

 colour of the protoplasm filling the apex of the tube, and 

 later on forming the spores. Beginning with bronze green it 

 gradually becomes reddish brown, or violet brown ; its 

 surface is shining, and exhibits iridescent reflections and a 

 bright metallic lustre, a circumstance to which the plant 

 owes its specific name and which allows of its immediate 

 identification. The membrane of the sporangium encrusts 

 itself, on the contrary, with calcium oxalates, which gives it a 

 dull and velvety aspect and renders it opaque and dark. 



We will now trace the progressive advance in the vigour 

 of the fructification which accompanies the more vigorous 

 growth of the mycelium in diff'erent nutritive media. 



In a drop of the saline solution the spores form a 

 mycelium which begin to fructify at the end of the second 

 day ; the spores are mature about sixty-five hours from the 

 time of sowing, the temperature being 57° F. The first 

 sporangiferous hyphae are not more than '100 mm. in length, 

 and may even be no longer than ■024 mm.; the corresponding 

 diameter of the sporangium may be no more than •025 mm., 

 and it may contain as few as ten spores with a very depressed 

 columella. The hyphae produced on successsive days become 

 gradually taller with sporangia correspondingly larger ; their 

 columella, which is more and more prominent, becomes at 

 first hemispherical, then cylindrical, and the spores are more 

 oval and more numerous. These changes are all concomitant. 

 At length, after twelve days, the sporangiferous hyphae pro- 

 duced outside the cells on the mycelium which has insinuated 

 itself between the covering glass and the cell have a length 

 of as much as seven to eight centimetres, a proportional 

 breadth, and a very large sporangium. Such a result is no 

 doubt astonishing when one reflects that, before the formation 

 of a hypha of this kind takes place, the mycelium nourished 

 by this minute drop of a saline solution has produced suc- 

 cessively larger and larger sporangia. It is still more 



