1870. J BOTANY AND ZOOLOGY. 101 



hence the common name, Sea Colander, by which they are 

 known. This species grows below low water mark, and is thrown 

 up in quantities by southern gales at Point Pleasant. It extends 

 from Greenland to Cape Cod, and has likewise been collected on 

 the coast of Russian America, but it is unknown on the European 

 shores. 



A. pertuswnu — Newfoundland. This plant is distinguished by 

 its less regularly shaped and smaller and fewer perforations.. 



Chorda filum. — The frond is of great length attached by a small 

 disc and very slender at the base, thickening towards the middle, 

 and again attenuating. It is often so long that when taken out 

 of the water it ressembles a fishing line. It occurs between tide 

 marks and extends into deep water, and is often abundant. 



C. lomentaria. — Extends from our coast south to Charleston, 

 o. C 



Dr. Lawson, in conclusion, read a letter from Dr. A. F. Le- 

 Jolis, of Cherbourg, France, in which he states — that he is engaged 

 in a monograph of the whole group of the Laminariaceas, that 

 for such a study materials are never too numerous, and that he 

 would be happy to receive a fresh supply of specimens from North 

 Amer^'ca. He asks Dr. Lawson's help, and that he would inte- 

 rest his friends in his favour. It is not necessary that the 

 specimens be prepared for the herbarium. On the contrary, he 

 had rather they were coarsely dried, without being washed in fresh 

 water or compressed. The parcels may be addressed to him, 

 and sent by any vessel sailing for France, or, if convenient, 

 through the steam packets from New York to Hamburg, which 

 stop at Cherbourg on their return from America. — Newspaper 

 Report. 



The Diffusion of Plants. — Prof. Delpino, of Florence, has 

 published some interesting researches on the relation between the 

 diffusion of plants and animals. The life of every plant has three 

 principal objects : its nourishment, its reproduction and the 

 distribution of its seeds ; for each of these three objects special 

 bio logical conditions being requisite. The fertilisation of many 

 plants can be effected only by some particular animal : as Arum 

 italicum, Aristolochia, and Asaimm, by gnats ; the fig tribe by 

 different species of Cynips (or gall-fly) ; Arum dracunailus, Sta. 

 pelia, and Rafflesia, by blue-bottle flies ; many others by different 

 kinds of flies or bee-like insects (^Hymenopterd) , and some even 



