LINNEAN SOCIETY OF LONDON. IxVli 



of the science, learnt at the same time how much there then re- 

 mained to be discovered in that branch of the vegetable kingdom. 

 In the winter of 1840 Thuret went to the East and brought some 

 marine Algae from the Bosphorus. In the following summer he 

 was at Lyons, where he studied geology under Fournet, making 

 excursions in company with Seringe and Jordan. 



At this time he was working hard at the microscope, the result 

 of which was his first work on the antheridia of Chara. In Octo- 

 ber of the same year he went as Attache to the Erench Embassy 

 at Constantinople. Here he studied the phaenogams, and in the 

 collection which he made there Boissier found some novelties. In 

 the middle of October in the following year he went on furlough, 

 travelling in Syria and Egypt ; but having been taken seriously 

 ill at Thebes, he returned to France. At this time he thought it 

 necessary to make bis plans for the future, and determined to 

 enter the Civil Service. Fortunately for science, his attempts to 

 do this were not successful, and he constructed for himself a labo- 

 ratory at Eentilly, and commenced working earnestly at the mi- 

 croscopic investigations of the Algae, the result of which was his 

 two works ' On the Motile Organs of Alg* ' (1843), and ' The De- 

 velopment of Nostoc ' (1844). In the year 1844 Thuret, in com- 

 pany with Decaisne, made his first algological excursion to the sea- 

 coast for the purpose of studying the reproductive organs of the 

 FucacecB, the result of which was their joint work published in 

 the same year. In the following year the two friends went to 

 Arromanches. Here they discovered for the first time the zoo- 

 spores of Chorda Filum, L., and ascertained that the so-called 

 spores of the brown Algae were probably reproductive organs or 

 sporangia. From this time Thuret went to the sea-coast every 

 year, sometimes in Normandy and sometimes in Britanny, either 

 alone or in company with Riocreux, and collected materials for 

 the essay for which in 1850 the prize of the Academy of Paris was 

 awarded. This work was entitled ' Eecherches sur les Zoospores 

 des Algues et les Antheridies des Cryptogames.' In the next 

 year he settled at Cherbourg with the view of studying the phy- 

 siology of the Algae, and where during his first winter residence 

 he made his discovery of the fructification of the Fueacece, a work 

 of the greatest importance, of which it may be said that it afforded 

 the first direct proof of the sexuality of the Algae. From Cher- 

 bourg he made expeditions sometimes to Biarritz and sometimes to 

 the Mediterranean, which excursions produced his other essays 



LINN. PEOC. — Session 1874-75. g 



