VOL. XXIX.J PHILOSOPHICAL TRANSACTIONS. 257 



We may observe, that when the 4th, or innermost bark c, has once com- 

 pleated its sap-vessels, and is firmly joined to the wooden part, then the third 

 bark o takes its place for the succeeding year ; and so the rest, only that the 

 first, marked m, splits and divides itself, to supply the place of the second. 



Before concluding I beg leave to recommend the following inquiry to the 

 curious, viz. If the several barks, having different texture of parts, admit into 

 each separate and different juices from the rest: whether those juices may not 

 be of very different virtues ; the first more astringent than the others, the 

 second perhaps emetic ; and the third cathartic. 



Some Microscopical Observations, and Curious Remarks on the Vegetation, and 

 exceedingly quick Propagation of Moldiness, on the Substance of a Melon, 

 Communicated by the same. N° 340, p. 49O. 



I had lately a large melon, which I split lengthwise through the middle, to 

 observe the vessels which composed the membrane or tunic of each ovary; but 

 my affairs at that time not permitting me to continue the work I had begun, I 

 laid by the one half of the melon, to be examined when I might have more 

 leisure. After 4 days, I found several spots of moldiness began to appear on 

 the fleshy or pulpy part of the fruit, somewhat green towards the rind ; and of 

 a paler colour towards the middle of the fruit. These spots grew larger every 

 hour, for the space of 5 days ; at which time the whole fruit was quite covered 

 over. This surprising vegetation made me curious to examine, if there was any 

 difference between those parts which were green and the others, besides their 

 colour. The first being seen with the microscope, appeared to be a fungus, as 

 fig. 7, pi. 5, whose cap was filled with little seeds, to the number of about 500; 

 which shed themselves in 1 minutes after they had been in the glasses. 



The other sort had many grass-like leaves, among which appeared some 

 stalks with fruit on their top. Each plant might well enough be compared to a 

 sort of bull-rush, as fig. 8. They had their seed in great quantities, which I 

 believe were not longer than 3 hours before they began to vegetate ; and it was 

 about 6 hours more before the plants were wholly perfected : for, about 7 

 o'clock one morning, I found 3 plants at some distance from any others ; and 

 about 4 the same day, I could discern above 500 more growing in a cluster with 

 them, which I supposed were seedling-plants of that day. The seed of all these 

 were then ripe and falling. 



When the whole fruit had been thus covered with mold for 6 days, this 

 vegetable quality began to abate, and was entirely gone in 2 days more. Then 

 was the fruit putrefied, and its fleshy parts now yielded no more than a stinking 



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