384 PHILOSOPHICAL TRANSACTIONS. [aNNO 1747- 



and spring from those branches, in the same manner as the leaves, the flowers, 

 and the fruits of a vegetable, spring from the branches of the same. 



It is nevertheless the contrary of all this that is true. The branches, compos- 

 ing the clusters of the polypi, spring from the polypi which are at their extremities. 

 These polypi, which at the first appear to be the fruits of the clusters, may more 

 properly be considered as their roots: and of the truth of this any one may easily 

 satisfy himself, who will be at the trouble of examining regularly, and for some 

 continuance, the whole progress of a cluster of these polypi. What further 

 proves that these branches do really spring from the polypi, and that they derive 

 their nourishment from the same, is, that the branches constantly cease to grow, 

 whenever the polypi at their extremities are detached from them, either natundly 

 or by any accident. 



There is another species of polypi which form also a groupe resembling a cluster, 

 or more properly an open flower. This flower or cluster is supported by a very 

 distinct stem, which is by its lower extremity fixed to some of the aquatic plants or 

 extraneous bodies found in the water. From the other extremity of this stem 

 issue out 8 or 9 branches, quite differently disposed from those of that species of 

 polypi he last described. These 8 or Q branches are perfectly alike, but it may be 

 noted, that what is here called by the name of a branch, is indeed the assemblage 

 of several other smaller branches, whose collective form much resembles that of 

 a leaf, fig. 10. Every one of these assemblages is composed of one principal 

 branch or nerve, which makes with the main stem of the cluster an angle some- 

 what greater than a right one. From either side of this principal nerve others 

 again set out, and these lateral ones are the less extended in length, the nearer 

 their origin is to the extremity of their principal branch. There is a polypus at 

 the extremity of this principal branch, and another at the extremity of every one 

 of the lateral twigs. There are others also on both sides of those lateral twigs, at 

 different distances from their extremities, and these are more in number or fewer, 

 in some proportion to the length of the twig itself. These polypi are all exceedingly 

 small, and of a bell-like figure, and they discover about their openings a quick 

 motion, very difficult to be seen with any distinctness. 



There may also be observed in several places, on the branches of these clusters 

 of polypi, fig. 10, certain round bodies, which Mr. T. at the first took for in- 

 sects preying on the polypi, because he was acquainted with some such, nearly 

 of that shape and size; but it is afterwards mentioned what those round bodies 

 really are. 



Every cluster has 8 or Q of these branches or leaves, such as he has described. 

 They do not all of them set out from the same point; but the points from 

 whence they set out are not far asunder; each of these leaves is a little bent in- 

 wards, and they all form together a sort of a shallow chalice or cup. If the eye 



