of the Vegetable Ovule. 17 



et ce prolongement forme lc raphe." I was led into error of 

 argument, as I have mentioned, solely hy my faith in the truth 

 of this last consideration, a doubt of the correctness of which 

 never crossed my mind, taught as it was by such eminent 

 authorities. 



The definition of Prof. Lindley (Introd. p. 180) is less expli- 

 cit, and therefore less objectionable ; but he evidently entertained 

 a similar view, though expressed in different terms. He states 

 that in this kind of ovule " one of its sides grows rapidly, while 

 the opposite side does not grow at all, so that the point (foramen) 

 of the ovule is gradually pushed round to tlie base, while, corre- 

 spondingly, the base of the nucleus is removed from the hilum to 

 the opposite extremity ; and when this process is completed, the 

 whole of the inside of the ovule is reversed." It is needless to 

 repeat that this definition is founded upon misconception, or on 

 too much faith in the erroneous descriptions of Mirbel and 

 St.-Hilaire. 



Dr. Fritsche (in 1835) was the first who impugned in part the 

 accuracy of MirbeFs observations on the development of the 

 ovule in Cucurbita. Mirbel had described the first indication of 

 the growing ovule as a simple cylindrical shoot protruding from 

 the placenta, which after a while exhibits a point, somewhat ex- 

 centrically placed near its apex, out of w r hich the nucleus forces 

 an opening ; this nucleus continues to grow, becoming sur- 

 rounded at its base by an annular ring, the rudiment of the 

 secundine, while the lacerated opening out of which the nucleus 

 springs forms the mouth of the primine and gives rise to 

 the outer coat of the ovule. Fritsche confirms the accuracy of 

 the appearances thus described, but contends* that the nucleus 

 does not originate in a sort of coleorhizal protrusion as narrated 

 by Mirbel, but that the whole placental shoot in question is in 

 reality the nucleus upon its funicular support, before any indi- 

 cation of the primine and secundine : this shoot is covered by a 

 single epidermal layer of cellular structure ; and at some little 

 distance from its extremity a double circular constriction is 

 formed, thus leaving a prominent annular ring round the pa- 

 pilla, which remains as the nucleus, while the portion of the 

 epidermis between the two strictures separates from the internal 

 parenchyma and becomes plicated, so that its folded surfaces 

 unite together in the form of a short tube, thus giving origin to 

 the future secundine. Subsequently that portion of the epi- 

 dermis below the strictures also separates and becomes folded 

 in like manner, thus giving rise to the future primine. This 

 assumption of the separation of the epidermis I believe to be 

 quite erroneous, for reasons presently to be given ; and it will 

 * Wiegmann's Archiv, i. 2 Band, p. 229. 



Ann. ty Mag. N. Hist. Ser. 3. Vol. iv. 2 



