250 NOTICES OF BOOKS. 



must be worked up when there is no po?sibility of access to growing 

 material, and he adds a hope that the Orchids of Australia will find a 

 student in their native home. It is with great pleasure that we 

 announce such a desideratum in the person of Mr. Fitzgerald, who 

 has publislied at Sydney the first part, consisting of introduction, and 

 seven folio plates with accompanying explanation, of a work designed 

 to make known the floral structure and function, and specific and 

 generic limitation of this group of plants. This first part we have 

 read with much interest, and we hope that the following account may 

 induce others to follow our example. 



The genus Pterostylis (plates 2 and 3) exhibits a very singular 

 method of fertilisation. Ii^ P. longtfolia the labellum is placed on a 

 slender hinge, and on tno slightest touch it springs up towards the 

 column. The pollinia are ensconced in a position just above the 

 wings of the much-dilated rostellum, in such a way that an insect 

 touching the labellum is carried against the column, and in order to 

 get out of the flower is obliged to pass between the rostellum- wings, 

 thus remowing the pollen-masses, which, on its alighting on the 

 labellum of another flower, are carried against its stigma 



In Caladenia dimorpha, a supposed new species, about which aa 

 about all similar cases we would earnestly recommend Mr. Fitzgerald 

 to communicate with Baron von Mueller or with European authorities, 

 we have another instance of an irritable labellum ; but the action of 

 the I'crtilising insect is essentially diff'crent, inasmuch as it becomes 

 entangled in the utricular stigmatic mass, in endeavouring to escape 

 from which, the pollinia, placed just over the stigma, are removed, 

 Plate 5 represents the two species of Corysanthcs {C. Jimhriata, Br., and 

 C. pniimsa, Cunn.), united by Mr. Beutham, but held to be distinct 

 by the author ; this genus has very small sepals and petals, but as a 

 compensation a vast amount of energy is concentrated on the label- 

 lum, which is very large and has numerous appendages, though con- 

 cerning the use of these Mr. Fitzgerald has nothing definite to 

 communicate. In the case o{ Acianthus, which has a forward-arching 

 column near the top, but on the underside of which the stigma is 

 placed, so that pollinia removed by insect agency strike against the 

 overhanging back portion of the column, the author believes that 

 fertilisation is eff"ectcd by small crawling insects. This brings us to 

 the last plate, which is occupied by Lyperanthtis, a critical genus 

 whose floral parts possess little functional interest. 



From among a number of incidental facts and inferences we select 

 the following. Thclymiira carnea is fertilised in the bud, the pollen- 

 masses crumbling upon the stigma, and the flower seldom opens and 

 never until aiter feitilisation. 2\ hngifolia is also in the same 

 condition. "With regard to Acranilms sesquipedalis, Mr. Fitzgerald 

 thinks that the spur may be v.sed as a retreat or as food by fertili- 

 sing insects, and a very ingenious suggestion is broached concerning 

 Uendrohium, in which a caterpillar or other insect, " by devouring the 

 top of the column, would be particularly likely to cause fertilisation, 

 as the pollen-masses, when the division between the clinandrium and 

 stigmfitic chamber is eaten away, would be likely to fall into 

 it." This suggestion is well worthy of trial on other Malaxideous 

 genera ; we have ourselves been often puzzled to account for the way 



