REVIEW. 409 



importance are the structure of the cystocarp and the for- 

 mation of the nucleus, and from long experience he ex- 

 presses his conviction that where these characters do not 

 agree there is no affinity. He had previously carried out 

 this principle in his arrangement of the Rhodomelem (Vol. 

 II, Part III), whose forms from lowest to highest form a 

 continuous and natural ascending series. Besides the cysto- 

 carps, the various forms of sphseosporic fruit have been 

 made use of in the classification wherever it was possible. 



As to the " Trichogyne/' of which so much has recently 

 been written, it will be more satisfactory to the reader for 

 the author to express his own views in his own language. 

 He says (p. v) — 



" Me in hoc volumine, quod potissimum dispositionera et 

 descriptionem formarum spectat, nihil dixisse de organis^ 

 quee maximi momenti considerarunt alii — de trichogynico ad 

 paratu et corpusculis antheridiorum, horumque organorum 

 functionibus — ignoscant precor. Quicumque oculo paulisper 

 critico observationes et conclusiones inde deductas repetat, 

 vix non videat observationes hucusque factas et ulterius re- 

 petendas et corroborandas esse. Mihi ipsi, adparatum tri- 

 chogynicura in pluribus quserenti, an unquam verum videre 

 contigerit, nescio. In iis cytocarpiis, quee transformatione 

 ramuli oriri videntur, ramuli transformati apicem fere sub 

 ea forma nunc in fructu juvenili persistentem vidi, quam 

 trichophorico adparatui tribuant. Confiteor me his locis in 

 hoc adparatu nihil suspicasse, nisi apicem ramuli, ob 

 evolutionem fructus hebetatum et sensim obsoletum. In 

 Dudresnaja totam evolutionem nuclei a filo generante obser- 

 vare credidi; hoc loco evidentissimum mihi adparuit filum 

 elongatum, quod nucleam superat, nihil esse nisi apicem 

 sterilem decoloratum fili nucleum generantis. Quod attinet 

 eos minutissimos globulos, qui corpuscula antheridiorum, 

 trichogynis adfixa sisterent, patet eadem quoad originem et 

 naturam omnino dubia esse. Non tantum ssepissime evenit 

 ut in gutta aquse corpuscula diversissimse naturae circuni- 

 vehantur, sed etiam practicis algologis bene constat sporas 

 algarum et particulas diversse naturae Algis ssepe adfixas 

 obvenire. Quomodo igitur probetur corpuscula ilia, quae 

 trichogynis adfixa viderunt, fuisse corpuscula ex antheridiis 

 provenientia, et ex antheridiis ejus speciei, quae iisdem 

 foecundaretur ? Si constaret antheridiorum corpuscula esse 

 agilia, facilius quidem intelligeretur corpuscula antheridiorum 

 trichogynicum adparatum potuisse attingere; sed corpuscula 

 omni mobilitate destituta contendit ipse Thuret. Si deni- 

 que qui ad totam rem illustrandam plurima contulerunt de 



