202 PHILOSOPHICAL TKANSACTIONS, [aNNO 1746. 



oval farina, «o extremely minute, as to be visible only with the most powerful 

 magnitiers in the double microscope. 



The outer membrane of the head becomes separable from the capsule when 

 perfectly ripe and dry ; and then, viewed in the double microscope, shows a 

 reticular texture, not visible in it before. When this head is first produced from 

 the plant, the stamina are very slender, and stand erect ; the head is scarcely any 

 thicker than the stalk, and the calyptra covers the whole, to shield the tender 

 substance of the farina from external injuries. As the farina afterwards swells in 

 the stamina, the seeds also in the head increase in bulk, and become visible, and 

 are then transparent ; but when it is perfectly ripe, the calyptra falls ofi^ and the 

 wind dislodging the farina at times, as it ripens some sooner, some later, it 

 makes its way through the pistillum into the head, and the seeds then become 

 much larger and opaque ; to favour the falling of the farina into the pistillum, 

 the stamina, as they ripen, are, by the increase of thickness in the head, thrown 

 farther and farther from each other at their bases, but bend inward at the points, 

 so as to form a kind of arch over the opening of it. 



The annual product of these most minute seeds is astonishing. An ingenious 

 gentleman has given, in N° 468 of these Transactions, an account of the won- 

 derful increase of the mallow; one of which he found to yield, in one year, 

 200,000. But this is much inferior to those of the little plant before us ; for, 

 allowing to a root of this 8 branches, and to each branch 6 heads, the produce 

 of this is 6 X 13824 = 82944, and 8 X 82944 = 663552 seeds, the annual 

 produce of one seed ; 13824 of which are contained in a head, whose length is 

 but -^ of an inch ; and its diameter but ^ of an inch, and whose weight is but 

 the 13th part of a grain.* 



PI. 4, fig. 7 shows the head of this moss in its natural dimensions, with 

 and without the calyptra. Fig. 8, the same viewed through a powerful magni- 

 fier, without its calyptra. Fig. 9, a longitudinal section of the same. Fig. 10, 

 stamina taken off fi-om the head, and viewed by a more powerful magnifier. 

 Fig. 1 ] , a piece of the outer membrane of the head, showing its reticular texture. 



Concerning the minute Eels in Paste being Viviparous. By Mr. James Sherwood, 



Surgeon. N" 478, p. Q7 . 



Examining one day a number of these eels, and viewing a single one, Mr. S. 



found he had wounded it in the belly ; a long slender tube proceeded from the 



wound, doubled in the form of an intestine, which he then took it for. Next 



day he communicated this to Mr. Turberville Needham ; and having a mind to 



* Dr. H.'s observation is correct, so far as relates to the seed of this moss j but if Hedwig's theory of 

 the fructification of the mosses be just, it follows that the organs supposed by Hill to be stamina, are 

 of a very different nature, and form what Hedwig calls the peristoma. 



