lOa PHILOSOPHICAL TRANSACTIONS. [aNNO 1764, 



stalk of a plant, and presenting it to her, she directly fell to work upon it, as 

 he held it in his hand. It was very wonderful to see how dextrously she worked 

 her dart into the stalk, at every puncture dropping an egg. This was seen very 

 distinctly, as she did not touch the stalk with any other part of her body. The 

 cicadae fix on most sort of trees, but like best the oak and chestnut ; also the sas- 

 safras, and all orchard trees. They always dart to the {lith of the branch, that 

 when the egg hatches, the little insect may find soft food in its infant state. 

 When mature they creep forth, go down the tree, or drop off, and soon make 

 their way into the ground, where they have been found 2 feet deep. Here they 

 find a secure repose, till they have passed through their changes, from a maggot 

 to a hexapode, and lastly to a fly. 



July 15th and l6th they were perceived coming forth : several darted twigs 

 wer« perceived, and carefully examined, and opened: some eggs were hatched, 

 others not mature, of a dull brown colour. These were taken out, and spread 

 on a table; in about an hour the eggs cracked. It was very entertaining to ob- 

 serve how the little insect contrived to disengage itself from the shell. When it 

 was got clear from its incumbrances, it ran about very briskly, seeking a reposi- 

 tory in the earth. 



Some General Remarks. 



These cicadae are spread all over the country in a few days; but being the prey 

 of so many animals, their numbers soon decrease, and their duration by the order 

 of nature being short, they quickly disappear. They are the food of most kinds 

 of domestic and wild fowl, and many beasts: even the squirrels grow fat with feed- 

 ing on them. And one of the repasts of the Indians, after having first plucked 

 off their wings, is to boil and eat them. There are two distinct species of cicadae 

 in North America; the one here described being much larger than the other. 

 The lesser species has a black body, with golden eyes, and remarkable yellow 

 veined wings. 



XI. Of the Plague at Constantinople. By Mordach Mackenzie, M. D. Dated 

 Constantinople, St. George''s Day, 1763. p. (]q. 



So many great men have written on the plague, such as Prosper Alpinus, 

 Sydenham, Hodges, Diemerbroeck, Muratori, Mead, &c. that Dr. M. re- 

 marks it might be justly thought presumptuous in him to touch upon that sub- 

 ject after them. But as he finds that they differ in some circumstances, and 

 that some of them have had an opportunity of seeing only one year's plague; he 

 may (he thinks) be allowed to write such remarks, as he had made for almost 

 30 years, that he had lived in Turkey, without any quotations or confirmations 

 from other authors; which he hoped would help to reconcile the different opi- 

 nions of the above-mentioned authors. 



