S PHILOSOPHICAL TRANSACTIONS. [anNO 1750. 



Concerning the Green Mould on Fire-wood ; with some Observations of Mr. 



Baker s on the Minuteness of the Seeds- of some Plants.* By the Rev. Henry 



Miles, D.D., F.R.S. N" 494, p. 334. 



Happening to take notice of a quantity of what is commonly called mould, 

 of a bright verdigrise colour, on the bark of some fire-wood. Dr. M. viewed 

 it with a lens, o{ about an inch focus, which he then found to consist of num- 

 bers of minute funguses, whose regular appearance invited him to examine 

 them in the microscope, with a good magnifier; when their spherical heads 

 seemed as if they had been nothing else but globules of seeds ; at the same time, 

 he observed several seeds adhering to the transparent foot-stalks, which supported 

 the heads, and many scattered on the glass plate, where the substance was placed, 

 in order to be viewed. And here he saw many distinct seeds, which appeared 

 nearly of an oval form, but several times larger than the seeds of common mush- 

 rooms, even when seen with the second magnifier, and the latter with the first. 



Having often viewed the heads of a small kind of fungus, which are about -f 

 inch diameter, of a coriaceous substance, he always found the seeds, which are 

 produced on the gills, much larger than those of any mushrooms he ever exa- 

 mined, though rather less than those produced by this unregarded plant. 



Now, that a body whose form is not to be distinguished by the unassisted eye, 

 should produce seeds several times larger than another of the same genus does, 

 which exceeds it many millions of times in bulk, must suggest very curious 

 thoughts to our mind. 



Some Observations on the above-mentioned Plants and Seeds. By Henry Baker, 



F.R.S. N°494, p. 337. 



Mr. B. carefully examined the plants and seeds sent him by Dr. Miles, in 

 order to determine their real size; and he found that the diameter of these fun- 

 gous bodies was at a medium, the 210th part of an inch. The seeds were oval ; 

 and the medium of each diameter was the 2430th part of an inch. 



And according to these calculations, 44,100 of the fungous heads, or 

 5,904,900 of the seeds may lie by each other in the surface of an inch square. 

 Yet, minute as the seeds of this little fungus are. Dr. Miles observes, very justly, 

 that they are larger than the seeds of some mushrooms, which exceed it many 

 millions of times in size. As to which, Mr. B. takes notice, that the proportion 

 in size, of the fruits or seeds of trees or plants, to the size of the trees or plants 

 that bear them, comes under no regulations that correspond with our concep- 

 tions. For the vast bulk of some sorts of timber-trees, the beech and ash for 

 instance, is produced from a seed smaller than that of the common garden bean. 

 The towering and mighty oak produces for its fruit only a little acorn, whereas 

 • The plant here described appears to be a species of the Limiaean genus Mucur. 



