1823.] Philosophical Transactions for 1823, Part L 221 



form, which, in its middle, is slightly contracted. These eggs con- 

 sist of an extremely thin and transparent membrane, through 

 which the young worm can be distinctly seen ; and, if atten- 

 tively observed, it may be seen moving within this envelope." 



The eggs, after the worms have quitted them, soon shrivel 

 and decay, and it appears that they ultimately dissolve. 



" The young worms are somewhat smaller and more trans- 

 parent than those which are found in the more mature grains, 

 but in a very short time after they have mixed with the others, 

 they cannot be distinguished from them. Those which are 

 found in the cavities of the mature grains, are nearly all of the 

 same size ; they are from -^ to -^ part of an inch in length, 

 and TTir-o P^^^ ^^ ^^ ^^^^ "^ diameter. - They are milk white, 

 semi-transparent ; and if viewed with the strongest magnifying 

 power, appear annular, like the large worms, though no exter- 

 nal indentations are observable ; they appear like fine glass 

 tubes filled with water, and containing many air bubbles in 

 close succession, and of the same number as the rings or 

 joints in the old worms. At both extremities (one of which is 

 more sharply pointed than the other), there are no such divi- 

 sions or joints perceptible. These extremities are each about 

 one-eighth of the whole length of the worm ; they are perfectly 

 transparent, and appear like solid glass. 



" The latter end of July, the diseased grains had almost all 

 attained their full size, and assumed a brownish tint; and 

 about the fifth of August they were all of a dark brown colour, 

 variously distorted, and as hard as wood. The cavities of 

 these grains were now completely filled with young worms, 

 and these worms were, in every respect, the same as those 

 with which I had inoculated my first seed grains ; and those 

 specimens were now more than twelve months old, and, conse- 

 quently, the grains and the worms within them were completely 

 dry ; but after soaking them in water about an hour, the worms 

 recovered their powers of moving, and were again as lively as 

 those which were taken from the living plants. 



" The large worms, after they become dry, die, and never 

 revive ; neither can the young worms within the eggs be re- 

 vived, if the eggs have been but for a moment dry before the 

 worms have extricated themselves." Mr. Bauer found that 

 such worms as had been kept the shortest time in water, reco- 

 vered their motions soonest; " so that those," he says, " which 

 had been examined in the plain object-glass, where only a very 

 small quantity of water can be applied, which very soon eva- 

 porates, almost every individual worm recovered in less than a 

 quarter of an hour ; and if the water is a second time suffered 

 soon to evaporate, the experiment may be repeated many times 

 successfully with the same worms; but after the second or 

 third repetition, if there is a suspension of a week or ten days 

 at each interval, several worms do not revive, and the number 

 of these increases at every succeeding repetition. If this ex- 



