FLORE DU NORD-OUEST DE l'aFRIQUE. 205 



of the phanerogamic vegetation of the highlands and of the Sahara 

 desert. The heavy and long-continued rains of the previous winter 

 in Algeria made the season very unfavourable for his investigation 

 there on the land plants, and induced him soon to proceed to Tunis, 

 where, favoured with the assistance of the French authorities, he 

 was enabled advantageously to carry out his scientific work. Before 

 returning home he spent some time at the Museum of Natural 

 History in Paris, where he availed himself of the opportunity there 

 offered to determine as precisely as possible the geographical distri- 

 bution of the new or imperfectly known forms of the plants included 

 in his treatise ; an exact knowledge of this distribution, especially 

 in the polymorphous groups of plants, he considers to be one of the 

 essential conditions for properly estimating the affinities and phyto- 

 genetic developments of the types. 



In the hope that the Compendium Flor(B Atlantic^ begun by Cosson 

 will be continued. Dr. Murbeck omits in general any description of 

 new species and forms contained in the museum, other than those 

 met with in his journey or such as are related more or less closely to 

 his own collections. If sometimes his determinations must be re- 

 garded as more or less approximate, he says that such is a necessary 

 consequence of the richness of the natural materials embraced in the 

 polymorphous groups which as yet are but imperfectly understood. 

 A conspicuous feature of this contribution consists in the 

 numerical statistics in metres, expressing the vertical range of the 

 Tunis plants of the collection ; many of the species and varieties 

 are recorded as extending up to 1300 or 1350 metres ; one, 

 Holosteum umbeUatnm L., a species new to the Tunis flora, to 1375 ; 

 and another, Alsine Alunbyi Boiss., also new to this flora, occurs 

 from 800 to 1400 metres of elevation. The treatise is very carefully 

 elaborated, and the literature of the subject accurately attended to. 

 In the thirty- six natural orders included in this part, there are re- 

 corded 430 species and hybrids distributed amongst 177 genera ; 

 there is one new genus ; and there are fourteen new species, besides 

 ten new subspecies. The sequence of orders is nearly that of Ben- 

 tham and Hooker ; but Cucurbitacea is placed after CampanulaceoB. 

 CarojjhyllacecB is split up into SiienacecB and Alsmacem and counts as 

 two orders, and Paronychiacea is placed next ; similarly the Bosacece 

 in the larger sense is divided into Amy gdalacece, RosacecB in a smaller 

 sense, and Pomacece, and counts as three orders ; and FumariaceeB, 

 in accordance with a prevalent view, is kept distinct from Papaver- 

 acecB. A new grammatical rendering is taken in treating Polygala as 

 neuter in gender, contrary to Pliny and subsequent authors. If it 

 is desirable to give effect to the gender of the Greek derivation of 

 the principal part of the word, it would have been better to have 

 followed the style of Dioscorides and to have written the name in 

 the form Polyyalon. The Polygala of Pliny probably belongs to a 

 different genus from that of the herbs now comprehended under this 

 name ; but this consideration need not affect the question of gender. 

 The plates contain eighty small figures from drawings drawn by 

 the author, and representing the flowers or other parts or dissections 

 of plants, and illustrate thirty-one species. The new genus is 



