64 



NOTICES OF BOOKS, 



Die natiirUchen PfianzenfamiUen . . . von A. Engler und K. Prantl. 

 i. Teil, 2 Abteilung [Alg^e] . Leipzig,: Engelmann. 1897. 



The volume devoted to Algae in Engler and Prantl's great work 

 is now completed. The Coujugatm, Chlorophycem, and CharacecE are 

 dealt with by Dr. Wille, the Phccophycew by Dr. Kjellman, and the 

 lUiodopliycecti by the late Dr. Schmitz, edited by Dr. Haiiptfleisch 

 and Prof. Falkenberg. The Conjugatm are divided as usual into the 

 three natural orders — DesmidiacecE, ZygnemacecE, srnd MesocarjnicetE ; 

 the ChlorophycecB into three groups — Protococcoide(B, Confervoidea;, 

 and Siponem ; and a plan is given of the relation which the various 

 natural orders of these groups bear to each other. In addition to 

 the diagnosis of large genera, such as Ulva, (Edogonium, Caulerpa, 

 &c., Dr. Wille has indicated the subdivisions into which the genus 

 is divided, and given a type of each such subdivision. It is to be 

 regretted that the genus Chlorodictyon has found its way into the 

 natural order Cmderpacea, as it is well known to be a lichen ; 

 Chlorodcsmis was shown to be but a state of Avrainvillea by Messrs. 

 Murray and Boodle in this Journal for 1889. Among the genera 

 of uncertain position placed at the end of Codiacem is J. E. Gray's 

 Codiophyllum, which belongs to FloridecB, and was sunk by Dr. 

 Agardh into Kiitzing's Tliamnoclonium . 



Dr. Kjellman, in his treatment of the Phaophycea, follows the 

 system of classificatiou published by him in his Skandinavieus 

 Ha fsidg flora, 1890, but in the reverse order. He divides them into 

 two groups — PhcBosporciE and CyclosporecE. The former he subdivides 

 into Zoogonicm and Acinet(E, Zoogonlca containing all the natural 

 orders of Phaospurece except PtllopterldacetE, which is placed by 

 itself in AclnetcE. Dr. Kjellman remarks on the impossibility of 

 forming a correct estimate of the position of the natural orders in 

 Phceosporew, owing to our lack of complete knowledge concerning 

 the reproductive organs of many of the genera. Much investigation 

 has yet to be done in this direction, though fresh light has been 

 thrown lately on several species of EctocarjxwecB by the valuable 

 work of M. Sauvageau, and on Taonia and Dlctyota by Mr. Lloyd 

 Williams. Dr. Kjellman has omitted to mention the important 

 link between Pucacc(B and LtnninariacecB which was discovered in 

 1892 by Miss Mitchell and Miss Whitting in the genus Splachnidimn. 

 This genus had till then always been classed among FiicacecE, but 

 the examination of its fruits showed that the supposed oogonia 

 were in reality zoosporangia growing in conceptacles — a distinct 

 connection between the PluEosporecB and CyclosporeiB of Dr. Kjellman. 

 This announcement, published in the Phycologlcal Memoirs, received 

 interesting confirmation a few months later from Mr. Laing of New 

 Zealand, who published a note on Splachnidiuvi riigosiim Grev. in 

 the Transactions of the New Zealand Institute. 



It may be noted in passing that the position of Splachnidimn as 

 type of a new natural order — SplacJmldiacea — has not been recog- 

 nized by Dr. De Toni in the volume on FucoidecE of his Sylloge 



