VOL. XXII.] PHILOSOPHICAL TRANSACTIONS. 5/7 



beating is a small greyish aniinal, much resembling a louse, when looked on 

 with the naked eye ; for which reason I call it pediculus pulsatorius. It is very 

 nimble in running to seek its shelter when disturbed. It is very common in all 

 parts of the house in the summer months. They are extremely shy of beating 

 when disturbed ; but will answer you when you beat, if you do not disturb them. 

 I cannot tell whether they beat in any other thing, but I have heard their noise 

 only in or near paper. 



Concerning their noise, I am somewhat in doubt, whether it be made by beat- 

 ing their heads or rather snouts against the paper ; or whether it be not made 

 after some such manner as grashoppers and crickets make their noise. I rather 

 incline to the former opinion. But my reason for doubting is, because I have 

 observed the animal's body give a sudden jirk at every stroke, but I could scarcely 

 perceive any part of it touch the paper. It is possible it might beat the paper, 

 and I not perceive it, as its body is small, and near the paper when it beats, 

 and its motion in beating is sudden and swift : for which reasons also it is hard 

 to perceive the insect to beat without a very quick eye : and therefore I made 

 use of a convex-glass, which by magnifying gave me much better opportunity of 

 observing it. 



I observed another, after much beating, come and make offers to the beating 

 insect ; who left off his beating, and got upon the back of the other. When 

 they had conjoined he got off again, and they continued some hours joined tail 

 to tail, like dog and bitch in coition, The female, which I saw, was somewhat 

 larger than the male, and of a lighter colour, inclining to a yellow. 



The Human Allantois fully discovered. By Rich. Hale, M. D. N° 27 1, p. 835. 



Most of the ancients allow a human allantois ; not from their experience, but 

 because they took it for granted that man and other animals were alike, in the 

 viscera, membranes, vessels, &:c. and the accounts which the ancients have left 

 of many parts, particularly of the urachus and allantois, as to its name, figure, 

 situation, &c. agree only to their appearance in brutes. Dr. Needham first dis- 

 covered part of the allantois in human subjects ; but neither he nor any other has 

 taken the right method of finding it entire. He says, that after the amnios is 

 cleared, and left fixed to the umbilical cord, you may divide by the fingers or a 

 knife, the remaining- part of the involucra into two membranes. The exterior 

 he justly calls the chorion, the interior he takes to be the allantois. But by 

 these ways of separation, you will presently tear the allantois, and be able to 

 discern only some small pieces of it. Besides the allantois is at first sight so 

 like the amnios, that many who suppose the amnios double, and that its coats 

 are easily separable, have taken these pieces of the allantois for broken parts of 



VOL. IV. 4 E 



