r i: I.SH-W ATKII AMJ.I: or TIM: r N i T i-: D STATES. 163 



the true /fi/i/'i.-/'!!,-' -. I lassall many years since descrilx-d bodies (Fre&- 

 w;itcr Alir.r, Mil. i. pp. 1 :>.', l-"ii>, 170), which lu- found in filaments of thisfamih, 

 and which resemble in all respects nrdinary ^fyj/fwywrai, but arc produced each 

 in ;i single cell wulnmt any aid from a second celL He affirmed that he had 

 observed this phenomenon especially in two species, Spirogyra mirabili* and 

 Zy</iinnn ii<>ttiltHI*. These observations were doubted by some, whilst others, as 

 Alexander Hnum, suppost <! that there was a division of the cell protoplasm into 

 two distinct portions, and then a conjugation of these within the original cell, and 

 that Mr. Hawaii had overlooked these changes. Prof. DC Bary, however, -states 

 that he has seen a great many instances of this production of spores without conju- 

 gation (all in one species), and that there can be no doubt that HassaH's obser- 

 vations are substantially correct, and that no division of the primordial utricle such 

 as \\as imagined by Prof. 13raun takes place. Spores formed in this manner, as 

 yet have not been seen to develop. There is, therefore, no certainty that they are 

 capable of doing so. It is possible that they are merely the results of abortive 

 attempts at reproduction, wanting the power of development because not fertilized. 



I'riiig^heim and others have drawn from these bodies strong argument against 

 the idea, that conjugation is to be looked upon at all as a sexual process. 



The arguments both for and against regarding conjugation as the simplest ex- 

 pression of sexual life are ably elaborated by De Bary, Untermdtungen iit>er die 

 l-'uiiii/i,' i/i r <\>i<jii<ititcin, p. 57, to which I must refer those desirous of following 

 the subject further, contenting myself with expressing an agreement with the con- 

 elisions there arrived at, namely, that in conjugation the first dawnings of sexuality 

 are to be found. Looking at it in this light Prof. Uc Bary states his conviction 

 that the spores formed in the manner last described, bear the same relation to the 

 true Xt/</"*/><>re that the bud of a Phanerogam docs to its seed, or the Zoospore of 

 an (!'.< 1 1 ><j< in i nm does to its resting spore. 



Quite a number of bodies have been described by the older authorities as being 



found within the cells of plants of this family, which more recent observers have 



proven to be parasitic. Such arc the "Spermatic spheres," transparent spheres 



motile by virtue of vibratile cilia, various monads, &c. &c., bodies for which it has 



D claimed, from time to time, that they were sexual elements, spermatozoids. 



Genus SPIROGYRA, LINK. 



C'rllulip vegetative cylindrical, fnsciis cliloropbyllosis spiralibus instructs:. Conjugatio aut later- 

 alls am M-iilariformis aut ct latcralis ct scalariforuris. 



. Spirogyra el Rhynchonema, K i T/.INU, RABENHGRST, et auctorea. 

 Salmacis, BORT. 

 Zygnema (pnrtim), HASSAI.I.. 



tntive cells cylindrical, furnished with spiral rhlorophyl bands. Conjugation either lateral 

 or Bcalariform or both latcrul and Bcalariform. 



Remark*. The genus Spirogyra, as defined above, has been divided by Kiitzing, 

 Rabenhont, and others into two genera, the characters being drawn from the 

 method of union of the conjugating cells; in the one case the neighboring cells of 

 a single filament (Rhyiichonema), in the other cells of distinct filaments 



