392 MOKPHOLOGY. 



sections from a young germen. Robert Brown * was here again the first 

 to strike out the true path, and showed, contrary to Mirbel's view, that 

 the original nucleus of the seed-bud does not open at the apex and allow 

 first the internal integument and then the true nucleus to grow forth 

 (hence Mirbel's mistaken application of the numbers in his names primine 

 and secundine), but that the inner and then the outer coat originate as 

 circular folds on the base of the originally solid nucleus, and gradually 

 envelope it. Fritsche's * observations did at least put the incorrectness 

 of Mirbel's views beyond doubt, if his own idea of the mode of formation 

 of the integuments was not wholly in accordance with the simple opera- 

 tions of nature. 



Brown, in his first works, has assumed the continual presence of two 

 integuments. Brongniart pointed out that seed-buds with one integument 

 undoubtedly occur. In Robert Brown's Treatise upon the Fecundation 

 of the Orchidacece, he called attention to the fact of the occurrence of the 

 naked seed-bud, after Mirbel had correctly developed the most important 

 curvatures presented by the seed-bud. 



Excepting Fritsche, who at the time of his writing was in St. Peters- 

 burgh, not a single German botanist has done anything on this weighty 

 point of our subject, not even so much as to re-examine the re- 

 searches of the distinguished Frenchman and Englishman ; and we find, 

 in consequence, even up to the most recent dates, the false views of 

 Mirbel, and these often sadly disfigured, copied without reflection. 



Using the observations of these men, I have made a large series of 

 investigations upon the development of the unimpregnated seed-bud in 

 plants of the most different families; and I have succeeded in verifying the 

 laws which had been laid down, modifying them in some subordinate 

 matters, and discovering a great body of facts, which are related in my 

 two treatises, " Einige Blicke auf die Entwicklungsgeschichte, &c.," 

 Wiegmann's Archiv., 1837, i, 289, and " Ueber Bildung des Eichens, &c.," 

 Act. A. C. L. C. N. C., vol. xix. P. I., p. 29. I have stated the main 

 points in the paragraphs. For the history of the development of a 

 reversed seed-bud with two integuments I refer to Plate IV., with 

 its explanation. I will now add a few remarks of subordinate im- 

 portance. 



The above-mentioned varieties of the seed-bud which arises from its 

 curvature are only the main types, and by no means embrace all possible 

 diversities ; nay, are only arbitrary distinctions, since between each of 

 those named occur intermediate forms which are difficult to reduce. No 

 definite laws, therefore, can be laid down for the occurrence of particular 

 forms, any more than for the number of integuments. Usually the same 

 form is constant in the same family, yet it does sometimes exhibit 

 deviations ; this, however, less in Dycotyledons than in Monocotyledons : 

 amongst the last, the family of the Aracece especially exhibits an endless 

 variety of forms of seed-bud. In order to aid the comprehension of the 

 various forms of seed-buds, and to lead to the examination in actual 

 specimens, I here offer some examples arranged as systematically as 

 is possible. The seed-buds are exhibited cut accurately in half by a 

 successful longitudinal section : 



* Observations on the Organs and Mode of Fecundation in Orehidacea and dsclepi- 

 dacete. Condon, 1831. 



f Wiegmann's Archiv, 1835, vol. ii. p. 229. 



