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lislifd ill l8.")() ; " Roclicrclu-s sur l;i Fceondutiori ilcs Fiiciiccrs suivius 

 tl'Obsorviitions sur Ics Anthcridies dcs Alp;ues," published in 1857; 

 and " lleclierchcs sur la Fecondution dcs Floridces," published in con- 

 junction with Dr. Bornet in 1867. The first-named work is an 

 abridgement of the essay which received tlic prize of the Academy, 

 and which Thuret intended to publish afterwards in full. Those who 

 study land plants have little idea how much labour was involved in 

 scarchinn; in all weathers for material for this work. The term spore, 

 as applied to the olive-coloured seaweeds, was used in the vajjuest 

 way. Thuret first showed that few of these bodies p;orminated as 

 simple spores, but that a great majority of them were sporangia, con- 

 taining zoospores in unicellular or pluricellular cavities. He defined 

 the Order PhcBosjmra;, and brought order out of confusion. He also 

 recognised the presence in this Order of bodies which he considered 

 to be aiitherozoids ; but he was never able to see the copulation of 

 zoospores described by Areschoug in Dicti/osiphon hippuroides. In 

 some of the green seaweeds, as Ulva, he recognised the presence of 

 two kinds of zoospores, the micro- and macrozoospores. The " Re- 

 cherches sur la Fecondation dcs Fucacces " seems to us the work in 

 which Thuret appears to best advantage as a writer. The subject itself 

 is interesting, and is admirably treated. It is a model of scientific 

 writing. An important physiological discovery, the fertilisation of a 

 mass of protoplasm by means of numerous antherozoids which cause 

 it to revolve and afterwards take on a coating of cellulose, is commu- 

 nicated in language neither too diffuse nor too concise. Here we see 

 the secret of bis success as a writer. He always tells his story simply, 

 without overwhelming the reader with unimportant details or beating 

 about in all directioi^s to. attract att(>ntion to his subject. The " Re- 

 cherches .sur la Fecondation des Floridces " illustrates the freedom 

 from preconceived theory which characterised Thuret. Naegeli had 

 figured a body which he dismissed with a short notice, as. on his 

 theory, it could have nothing to do with the fertilisation of Floridcm. 

 Struck by Na(>geli's figure, but not prejudiced by any peculiar view of 

 what fertilisation in the Floridecc ought to be. Thuret examined and 

 ibund in the body figured hy Naegeli the trichogyne, the key to the 

 undirstanding of the fertilisation in this Order. Thuret was a gene- 

 rous correspondent, and was in the habit of furnishing valuable notes 

 to his friends, some of which have become public. He wrote no 

 treatise on the classification of Algtc unfortunately, but in a note pub- 

 lished by Lejolis in his " Li.ste des Algues ]\Iarines de Cherbourg," he 

 gives briefly his views on this subject. Instead of regarding the 

 Fucacece as the highest of the Alga), he places the Floride<c at the head 

 of the list, a view with which most, if not all, recent writers agree. 



To compare Thuret with other algologists would he difficult. He 

 did not pretend to be able to determine foreign species as Agardh or 

 Harvey. Although his herbarium was large, he did not attempt to 

 increase his foreign exchanges, thinking that, beyond a certain point, 

 the collection mastered the botanist rather than the botanist the col- 

 lection. To him Alga? meant not the red and green things packed 

 away in herbaria, but the plants which cling to the rock, which wave 

 in pools, to which every returning tide brings a new phase of existence, 

 to which the change of season means death or a renewal ot life. 



