OCTOBEB 17, 1913] 



SCIENCE 



549 



(6 sp.), Pogoniris (31 sp.), Hexapogon (2 sp.), 

 and Dietes (4 sp.)- The genera Xiphion and 

 Juno, excluded by Baker bvit since merged in 

 Iris, included nearly 20 species, so that at that 

 time the known plants now regarded as spe- 

 cies of 7ns reached about 100. A few years 

 later (1892) when Baker published his " Hand- 

 book of the Irideae " the number of species 

 was increased to 161, distributed among ten 

 " subgenera " as he continued to regard them, 

 as against six in his earlier treatment. Com- 

 paring Baker's disposition of the species with 

 that of Dykes the greatest difference is to be 

 found in Pogoniris, to which Baker assigned 

 52 species, while the later author assigns to it 

 but 34 species. Xiphium with 14 species in 

 Baker's " Handbook," has but 6 in Dykes's 

 book. In some cases the later author has been 

 unable to identify certain old names, while in 

 others he has reduced them to synonymy. 



American students have found Hasselbring's 

 article " 7m " in Bailey's "Cyclopedia of 

 Horticulture " very helpful. His treatment 

 follows the general lines laid down by Baker, 

 and includes 102 species. 



Coming to the book before us one finds a 

 far fuller treatment than had previously been 

 accorded these plants, for here we have a bo- 

 tanical monograph of a generous type, in 

 which there is successfully combined accuracy 

 of scientific detail with popular directions to 

 growers. To these matters of fact are added 

 the exquisite colored drawings and fine print- 

 ing and binding which make this a work of 

 high artistic merit. 



The botanist will notice that the author di- 

 vides the genus into twelve sections, approxi- 

 mately equivalent to Baker's " subgenera." In 

 eight of these the underground portion of the 

 plant is a rhizome, while in the remaining sec- 

 tions it is bulbous (a bulb or corm). This 

 character at once divides the genus into two 

 parts — the " rhizomatous Irises," and the 

 " bulbous Irises," and after this the sections 

 are distinguished by their " smooth," 

 " crested " or merely " bearded " outer seg- 

 ments (falls), and the seed characters (aril- 

 late, non-arillate). One third of the species 

 (49) are found in the section Apogon with 



rhizomatous plants, and smooth falls, and 

 nearly one fourth (34) are in the section 

 Pogoniris with rhizomatous plants, and 

 bearded falls. In the first of these are Iris 

 versicolor, I. missouriensis, I. montana, I. 

 verna, etc., while in the second are 7. pumila 

 and 7. germanica, of our gardens. The sections 

 Onocyclus (rhizomatous, with sparsely bearded 

 falls; 16 sp.) and Juno (bulbous, with smooth 

 falls; 17 sp.), include less commonly known 

 species. The plants of the Juno section look 

 very unlike ordinary Irises, their leaves being 

 channeled, instead of sword-shaped, and the 

 standards are spreading, instead of erect. In 

 the Onocyclus section is found Iris lortetii, of 

 the southern slopes of Lebanon in Palestine, 

 " perhaps the most beautiful of all Irises." 

 Its large flower is quite remarkable, with its 

 nearly orbicular falls, orbicular, erect stand- 

 ards (3-4 inches in diameter) and arched, 

 crimson-red styles. " Unfortunately it seems 

 to be one of the most difficult to cultivate 

 among the difficult members of its class." 



This fine volume is destined to become the 

 standard book on Irif.es, and on this account 

 must be found in every botanical library, 

 while its beautiful piates, fine paper, print and 

 binding will cause j.t to find place in many pri- 

 vate libraries. 



Charles E. Bessey 



The Universitt of Nebraska 



Thought and Things, or Genetic Logic. Vol. 

 III., Part I. Real Logic. Interest and Art. 

 James Mark Baldwin. London, George 

 Allen and Company; New York, The Mac- 

 millan Company. 1911. Pp. xvi -f- 284. 

 This Part I. of Volume III. of Baldwin's 

 " Genetic Logic " opens with a resume of the 

 conclusions of the other two volumes, " with a 

 view to their bearing on the problem of 

 reality." The " logic " of " affective experi- 

 ence " is discussed under the title The Logic 

 of Practise, in Part III.; Esthetic Experience 

 is discussed in Part IV. ; The Modes of Im- 

 mediacy are discussed in Part V. ; and in a 

 sixth part, the new term Pancalism (from the 

 motto of the work as a whole, to Ka\ov irav) is 

 proposed as a name for the author's philosophy, 



