220 Analifm of Book%, [Sept. 



month of October, 1807. Nearly all the seeds came soon up, 

 and I took from time to time," he continues, " some of the 

 young plants for examination, but could not perceive any effect 

 of the inoculation, till the month of March, 1808, when, in care- 

 fully slitting open the short stalk of a young plant, I found three 

 or four worms within it ; they were in every respect the same, 

 but they were now about two-thirds larger, as well in length as 

 in diameter, 



" On the 5th of June, I found, for the first time, some of the 

 worms, of different sizes, within the cavities of the young ger- 

 mens ; and having, in the beginning of March, found some of 

 them in an enlarged state in the stalk, I concluded that some of 

 the original worms, with which I had inoculated the grains of 

 seed, had got, during the germination of the grains, into the 

 stalk, where they became mature, and laid their numerous eggs, 

 some of which must be carried by the circulating sap into the 

 cavities of the then forming young germens, in which the young 

 worms extricate themselves from these eggs ; and finding their 

 proper nourishment within the cavities of the germens, these 

 young worms become of mature age, and lay their eggs within 

 the cavities of these germens, which, at that period, nearly 

 approach towards maturity ; and these newly laid eggs, I consi- 

 der to be the beginning of the third generation of the worms 

 with which I had inoculated the grains planted in the ground in 

 October, 1807. 



" Towards the end of June, the germens assumed various dis- 

 torted forms, and began to be filled with eggs. I extracted 

 carefully the whole contents of one of the largest grains, and 

 putting it into water in a watch-glass, I found, on examination 

 under the microscope, seven large worms, all ahve, bending and 

 twisting in the water like so many small serpents." 



The largest worms are more of a yellowish-white colour than 

 the young ones, and are not so transparent; from the head, 

 which is somewhat roundish, and furnished with a proboscis, as 

 mentioned in our report of this lecture, they taper gradually off 

 towards the tail, which is scarcely half the diameter of the mid- 

 dle of their body, and ends in an obtuse claw-like point. 



" The movements of these large worms are very faint and 

 slow ; they are very seldom observed to unroll themselves 

 entirely; they move their heads and tails faintly, but their pro- 

 boscis they move constantly, extending and contracting it 

 quickly ; and when in the act of discharging their eggs, they 

 bend the tail-piece upwards with a very quick jerk, at the pass- 

 ing of every egg ; after having discharged all their eggs, the 

 parent worms soon die, and in a few days they decay, and fall to 

 pieces almost at every joint. 



" The eggs come out from the orifice in strings of five or six, 

 adhering to one another at their ends, which then appear trun- 

 cated ; but, in water, they soon separate, and assume an oval 



