6 PHILOSOPHICAL TRANSACTIONS. [aNNO 1703. 



artery; k the pyloric artery ; 1, the larger gastric artery ; mm the splenic artery; 

 K the upper mesenteric artery ; l the phrenic arteries ; o the trunk of the vena 

 portae; pp the arteries and veins distributed over the mesentery. 



Concerning Green IVeeds growing in Watery and some Animalcula found about 

 them. By M. Lewenhoech, N° 283, p. 1304. 



I have often heard the common people say, that that green stuff or weeds, 

 observed to drive upon the water, spring out of the ground from under the 

 water. But as often as I have observed the said green weeds, I have always 

 found that they are produced from the seeds of the same kind, as all other trees 

 and plants are. I have always observed too that this green matter does not 

 grow in deep waters, though they are small and still ; but that it abounds in 

 wide and shallow waters, and especially moats and ditches ; and that the wind 

 does it no harm. I have also found that the green weeds in those ditches which 

 have but little water in them, are very small in comparison of those in larger 

 waters, and near the sides of the banks, where they are shallow, and very little 

 motion in them. 



Delft-haven belongs to our town, and lies about 2 hours distance from it ; 

 from that town, by means of a sluice, the water of the river Maes, with the 

 flood in summer time, is brought into our town, and it is as clear as if the river 

 itself ran through the town. With this water comes in also a little of this 

 green stuff, but so little, that we were half an hour a fishing up 30 of those 

 weeds, and putting them into an earthen pot, together with a large quantity of 

 their own water, for we took them up as deep as we could, that we might not 

 hurt their roots. 



I took out several of these weeds from the pot one by one, with a needle 

 very nicely, and put them into a glass tube of a finger's breadth, filled with 

 water, and also in a lesser tube, and caused the roots of the weeds to subside 

 leisurely ; then viewing them with my microscope, I observed a great many and 

 different kinds of animalcula, of which two sorts had long tails, by which they 

 seemed to be fastened to the roots of the weeds. These animalcula* were shaped 

 like a bell, and they moved the round cavity of their bodies in a manner that 

 they put the small parts of the water into such a motion, that I could not see 

 the instruments they used to produce it. 



And though I saw 20 of these animalcula together, gently moving their long 

 tails and outstretched bodies, they contracted their bodies and tails in an instant, 



* Vorticella ConvaUaria, Linn. 



