376 ANNUAL OF SCIENTIFIC DISCOVERY. 



animals, the normal twin embryo of the Polyzoa, the variable number of 

 ToMiia heads budded off by the Cystic Entozoa, and the phenomena of de- 

 velopment among the Echinodermata, were referred to as indicating a grad- 

 ual transition from the implantation of the embryo on the germ-mass of the 

 ordinary ovum, to cases of well-marked alternation while the reproduc- 

 tive process in the Poly/.oa and Hydraform Polypes, in the Salpas and in 

 some Annelides, and the phenomena of impregnation in the Coniferaj among 

 vegetables, were brought forward in illustration of a similar transition from 

 the development of the normal, reproductive organs, to the formation of 

 conspicuous sexual Zooids; and in proof of distinctions founded on the 

 complexity of the structures themselves not being of essential importance, 

 reference was made to the males of the Rotifera and Cirrhipeda, which, 

 though animals with an individuality entirely distinct even from the ovum, 

 are much more defective in organization than some of the sexual Zooids 

 now referred to, as the Hood-eyed Medusas. The paper was illustrated by 

 tabular views of the relations referred to. 



ON THE STRUCTURE OF PLANTS. 



One of the earliest fruits of the application of the convex lens to the exam- 

 ination of minute bodies, was the discovery of the structure of wood fibre, 

 and the arrangement of the minute vessels in which the sap of plants circu- 

 lates. Anxious to ascertain whether or no these microscopic A'essels inter- 

 communicated with each other, Professor Faraday took a stick of considera- 

 ble length, and having varnished one end, he cut his name through the 

 varnish, and forced a colored injection into the pores of the wood; when, 

 after some time, the name appeared at the other end, nearly in the same 

 relative position as that in which it had entered, thereby proving that the 

 sap vessels are completely separated from one another. 



ON THE AMELIORATION OF PLANTS FROM THE SEED. 



Among the valuable scientific publications, in France, of the past year, 

 are a collection and reprint of several of Louis Vilmorin's important commu- 

 nications to the Central Agricultural Society of France, and to the Academy 

 of Sciences; to which is prefixed a French translation of a memoir upon the 

 Amelioration of the Wild Carrot, contributed by his father to the Transac- 

 tions of the London Horticultural Society (but not before published in the 

 vernacular of the author), which memoir, as the younger Yilmorin informs 

 us, was the point of departure for his own investigations in this field, and 

 even contains the germ of most of the ideas which he has since developed 

 upon the theory of the amelioration of plants from the seed. These pa- 

 pers claim the attention of the philosophical naturalist no less than of the 

 practical horticulturist. 



Most of our esculent plants are deviations from the natural state of the 

 species, which have arisen under the' care and labor of man in very early 

 times. New varieties of these cultivated races are originated almost every 

 year, indeed; but between these particular varieties, the differences, however 

 well marked, are not to be compared for importance with those changes 

 wdiich the wild plant has generally undergone, in assuming the esculent 

 state. In this amelioration or alteration, as in other cases, c'est la premiere 

 pas que coiite. For the altered race, once originated, has much less stability 



