58 SYDNEY H. VINES. 



0)1 the Homologies of the Suspensor.^ By Sydney H. Vines, 

 V>.K., B.Sc, Fellow and Lecturer of Christ^s College, Cain- 

 bridge. (With Plate V.) 



The first definite account of this structure seems to have been 

 given by Mirbel.'^ He says, "un fil tres-delie, le suspenseur, 

 descend du sommet de Tovule dans la quintine, et porte a son 

 extremite un globule qui est I'embryon naissant." Robert Brown 

 also observed it in his investigation of the development of the 

 embryo of Orchids.^ He describes it as "a thread consisting of a 

 simple series of short cells .... the lowermost joint or cell of which 

 is probably the original state of what afterwards, from enlarge- 

 ment and deposition of granular matter, becomes the opaque 

 speck or rudiment of the future embryo." In his paper on 

 *' The Plurality and Develoj)meut of the Embryos in the Seeds of 

 Coniferse,^''* he states that in Finns s^hestris " this filament or 

 funiculus consisted generally of four series of elongated trans- 

 parent cells or vessels, usually adhering together," and further on 

 he adds, " the opaque granular extremity of the funiculus is 

 evidently the rudiment of an embryo." Hartig^ also described 

 and figured the suspensors of Conifers so early as 184-0. 



Mettenius** was a[)parently the first to detect the presence of a 

 similar organ in the developing embryo of a cryptogamic plant. 

 In his account of the changes taking place in the central cell 

 (oosphere) of thearchegonium oi Selaginella i?ivolve?is{?) in con- 

 sequence of fertilisation, he mentions that a suspensor (Embryo- 

 trjiger) is formed from its upper half. This observation was con- 

 firmed by Hofmeister in his "Vergleichende Untersuchungen"^'^ 

 and more recently the whole subject of the development of the em- 

 bryo of Selaginella has been investigated by Pfett'er,^ with results 

 which will be discussed hereafter. 



It is usually believed that the suspensor which is found in 

 Selaginella, in Gymnosperms (Archisperms), and in Angiosperms 

 (Metaspcrms), is a special organ, no trace of which is to be de- 



^ Suspenseur, Mirbel. Embryolrager, Keimtrdger , Keimstrang, Chorda em- 

 bryonalis^ Sclilciden and otlicrs. Keimscldauch, Uiiger. Vorkeim, Hof- 

 nicist.er. 



•■^ 'Ann. d. Sci. Nat. Jour.,' xvii. 1S29. 



' 'Trans. Ijinn. Soc.,' vol. xvi, lS3.'i. This paper is contained in the ' Col- 

 lecl,ed Wrilinfis of Kuhort Brown,' pul)lislicd by the ilay kSociety. 



* ' Ann. and Mag. of Nat. Hist.,' ISll. This paper is contained in the 

 'Collected Writings of Itobcrt Brown,' published by the iiay Society. 



' ' Naturgescii. d. fcirst. Culturjjflanzeu,' lSi-0. (Explanation of plate 



XXV.) 



« 'Beitrage zur Botanik.,' Heft 1, 1S50. 



'' Leipzig, 1S51. 



^ lu Hansteiu's ' Botanisclie Abliandlungcn,' Bd. i, 1871. 



