BOTANY. 353 



gested. Dr. Yoelcker stated that he had arrived at similar experimental con- 

 clusions as Dr. Gilbert, but while he acknowledged that starchy bread was 

 mechanically the best, he combated Dr. Gilbert's view, that this was the most 

 wholesome kind of bread for the working man. He traced the phosphoric 

 acid found by Dr. Gilbert in the bran to phosphorus contained as such in the 

 gluten, Dr. Yoelcker having found this element in caseine and legumine. 



MICROSCOPIC DISCOVERIES OF THE XATUEE OF BLIGHT IN 



WHEAT. 



M. C. Davaine has lately published in the Cornptes Bendus the result of his 

 researches into the nature of blight in wheat, of which account the following 

 is an abstract : Wheat is subject to a disease which in rainy seasons is very 

 prevalent in certain districts ; it is known under the name of blight. This 

 disease is caused by microscopic animalcules, whose organization is similar 

 to that of the cylindric worms which live as parasites in the vorticello and in 

 man. They are helminthes of the order of nematoides thread worms. These 

 wheat worms have the remarkable capability of remaining in a dry and horny 

 state for years, and then regaining life and motion on being moistened, and 

 this process can be repeated eight or ten tunes. It was long disputed whe- 

 ther they were animals or vegetables. On examining a grain of blighted 

 wheat, it is found to consist of a hard shell filled with white powder. This 

 powder contains no trace of starch ; it consists entirely of microscopic threads, 

 which are dry, stiff worms. When placed in water these worms exhibit 

 hygroscopic motion for a few moments. When the wheat is new they soon 

 make other manifold and considerable movements which are unmistakable 

 signs of life. When the grain is old it requires several hours, or sometimes 

 even days, before they resume motion and life. In a single grain of affected 

 wheat there are generally several thousands of these worms. They have no 

 sexual distinctions ; they are the offspring of other forms. Before a blight 

 comes on there are found from two to twelve larger worms in each kernel 

 which is about to be affected, and the females of these larger worms have 

 been observed to lay eggs. If blighted wheat is sown with sound, the worms, 

 after a few weeks, and when the sound wheat has germinated, are awakened 

 into life by the moisture of the earth, break through the thin shell which has 

 confined them, and follow the dictates of individual enterprise. The great 

 mass of them die an unfruitful death, but a few reach the germinated wheat 

 and effect a lodgment in the stalk under the forming leaves. They are car- 

 ried up by the growth of the plant, and in wet weather by their own exer- 

 tions. As they are dried up most of the time, they suffer no considerable 

 change until they enter into the forming kernels and lay their eggs. The 

 blighted wheat is no more grain than nutgalls are fruit Its tissue is com- 

 posed of hypertrophical cells. It is only after the worms have entered this 

 tissue that their reproductive organs become distinct. Both males and 

 females become much larger, but the females are larger than the males and 

 lay a multitude of eggs, in which can be seen an embryo that soon breaks 

 through the membrane of the egg and commences its larva life. By the time 

 the sound corn is ripe the parents are dead, their remains are dried into 



