NOTICES OF BOOKS AND MEMOIRS. 57 



encloses a part of the central space (bladder), which thus becomes 

 ultimately divided iiito two : to it great importance is attached as 

 an agent in effecting upraisal of the lid. The enveloping mem- 

 brane then bursts, and the swarm-spores immediately escape, 

 scarcely a minute being occupied in complete emptying of the 

 spore : in this latter there only remains the now spherical 

 *' bladder," to which are attached a number of small colourless 

 starch-grains, and a few solitary granules of chlorophyll. The 

 swarm- spores are 2-ciliated, and, as mentioned above, they usually 

 copulate, those that do not do so coming to grief. In copulation 

 usually two (but sometimes several) spores come together, but the 

 cilia remain free, and the motion of the united mass is swifter than 

 that of the individual members. The mass assumes rounded form 

 after a time, and the cilia are absorbed into it, and subsequently it 

 is surrounded by a thin membrane of cellulose. Copulation never 

 occurs between swarm-spores of the same spore. Sometimes a 

 crowd of united zoospores escapes from a spore, and swims about 

 like a copulated mass, which it much resembles, but it finally 

 comes to nothing. About five months after coagulation the mass 

 begins to germinate ; but we must refer those anxious to know 

 more about the vegetative life of the plant to the paper itself. 



The reproductive structure spoken of as a " siDore" is regarded 

 as a true spore, since it forms the asexual close of a sexually pro- 

 duced generation. For the swarm-spores the teim." gametes'' is 

 proposed, the spore being called ^^ (/ametaiigium." The mass of 

 copulated gametes is called a ^^ zygote'' — a term which is also 

 proposed as a substitute for zygospore and isospore, these not 

 being spores in Sachs' sense. An ingenious comparison is 

 drawn between the hypnospores of Botrydium and the spores of 

 Acetabularia. S. M. 



Bedfordshire Plant List for 1876 (being the Fu'st Eeport of the 

 Botanical Survey of Bedfordshire.) By W. Hillhouse, 

 F.L.S. 1877. 



The newly issued catalogue of Bedfordshire plants will speak 

 favourably for the industry of the Society which is its sponsor. 

 About 270 species have been added to the 430 included in the list 

 drawn up under the same auspices some twelve months previously. 

 But the roll has been unduly swollen by the admission, without 

 any sign of distinction, of several uon -British plants, some of 

 which, such as Pinus Pinaster, seem to be especially out of place 

 in a preliminary enumeration. The arrangement adopted com- 

 prises apparently only those species which have fallen under the 

 observation of members of the Society, and no notice is taken 

 even of contemporary records. It is not very clear how far the 

 statements and specimens of correspondents have been submitted 

 to the judgment of any central authority. Few botanists would 

 be inclined to admit, without some better evidence than is here 

 afforded, the occurrence as natives in the county of Viola lutea, 

 Vicia lutea, Callitriche autumnalis, and Carex limosa ; and their 



