Formula for sines an» cosines. IS 



seed is fit to receive impregnation; that it should then fall 

 off, and the fringe bend over the pointal, to mix the pollen 

 with the juice of the pistil ; and, to prevent the powder of the 

 stamen from being lost in the seeds, that a thick curtain 

 should be drawn between, to give time for the melting of 

 the powder in the sweet juices of the pistil; all this is 

 exactly conformable to the process in every other flower, 

 and analogous to the proceedings of every other plant. 

 But this is not all : that in all the rest of the cryptogamise 

 the males should be distinguished for excessive motion, and 

 yet in the mosses alone be different, is not to be credited. 

 Besides, when the supposed male flower is found ; it is often 

 not one to ten thousand females ; and considering, that 

 much powder must be lost in attaining the pistil, nature 

 would have provided a quantity, as it does in every other 

 case I am acquainted with, where the male flower is sepa- 

 rated from the female. These are all strong reasons for 

 believing, that the male plant has been generally mistaken. 

 But there is another source of errour admirably suited to Source of e> 



mislead. There is a species of animalcule, which lays its light rourm th f 

 . . •■ •• , , •■*' eggs of am- 



green eggs very often in some species of mosses; and gene- malcules 



rally chooses the upper leaves, whence they open to the ta ^" for 



stalk. These are so like pollen, that it is only keeping 



them till they hatch, that can prove what they are. I have 



been twice so deceived. I have added a dissection, at fig. 



4, of the stem of the moss/to show the manner in which the 



spiral wire runs from leaf to leaf at z ; and to show the 



ball, round which it winds at every leaf, thus running up 



the midrib. 



II. 



Trigonometrical Formula for Sines and Cosines. In a Let- 

 ter from a Correspondent. 



To W. NICHOLSON, Esq. 

 SIR, 



JV ROM your favourable reception of the Trigonometrical 

 Formulae, which I had the honour of communicating, and 



which 



