438 Scientific Intelligence. 



species that the forms called Halonia were the terminal divisions 

 of Lepidodendroid branches. This discovery is confirmed in the 

 present case, and proof advanced that not only Halonia, but 

 Ulodendrou as well, is a state belonging to branches that either 

 bore fruit or were destined ultimately to do so. He concludes that 

 the Ulodendron scars were produced by the pressure of strobiles 

 which were borne at the ends of lateral branches arrested before 

 fairly issuing from the parent branch, and that the distinction 

 between the Halonial and Ulodendroid condition is chiefly that 

 in the former, owing to the presence of a short peduncle, the stro- 

 bile produced no pressure disk but only a tubercular scar. All 

 these conditions are thoroughly illustrated in the plates. 



l. f. w. 



3. Fossil Plants as Tests of Climate; by A. C Seward. xii+ 

 151 pp., 8°, London, 1892. — This is the Sedgwick prize essay for 

 the year 1892, and the award was undoubtedly a just one. Geol- 

 ogists usually admit the value of plants as tests of climate, what- 

 ever they may think of their value in determining age. And yet 

 this work, which probably makes the most of this subject, shows 

 what a difficult one it is and how unsatisfactory most of the evi- 

 dence really is. We can indeed say with certainty from the ex- 

 istence of vegetable remains in the early Tertiary of the arctic 

 regions, similar in their general character to those now growing 

 in temperate climes, that a great change has taken place there 

 since that time. This is because we are dealing with forms so 

 well known to us that we feel that inferences based on the assump- 

 tion of their similarity in respect to the effect of temperatui'e are 

 tolerably safe. But when we go back to Carboniferous time the 

 force of such arguments is greatly reduced by our ignorance as to 

 whether similarity of form implies similarity in hardiness at such 

 widely separated periods. There are, nevertheless, many facts 

 that indicate a much warmer climate over the whole globe in 

 Paleozoic time than that which has since prevailed, among the 

 strongest of which is the complete disappearance of the leading 

 types at the close of that period, Avhich is now generally believed 

 to have been marked by a great fall, temporarily at least, in the 

 general temperature. The work is chiefly a compilation of facts 

 bearing on the problem, and the author wisely refrains from 

 sweeping deductions. The historical sketch and discussions of 

 distribution, temperatures, annual rings, etc., are attractive fea- 

 tures. The literature covered shows great research. l. f. w. 



4. Flora Tertiaria Italica, auctoribus A. Meschinelli and X. 

 Squinabol. 1 vol., 8°, pp. lxii + 578. Patavii, 1893. — This exhaus- 

 tive and scholarly work has been announced some time and is 

 highly welcome. It enumerates 1759 fossil plants, or all that are 

 known to the authors to have been reported from any of the Ter- 

 tiary deposits of Italy, and it aims to give all the information that 

 exists relative to every such plant. That is to say, the names are 

 followed by full bibliographical references, synonymy and brief 

 descriptions, as well as a statement of the exact locality and 



