SEXUALITY IN THE LO\VeR CRYPTOGAMIA. 69 



DC, from its earliest state up to the formation of the single ascus 

 and spores. In this process he notices two cells as being always 

 present and visible from the earliest period, one of which he calls 

 the **Ei-zelle," and the other the " Antheridium." The former 

 afterwards divides, and the ascus is the result of this division. De 

 Bary admits that the evidence of the sexuality of these organs is 

 not strong. '* However," he says, " it is certain that the cell by 

 " the division of which the ascus and its coating are formed, only 

 " develops itself when it has been in contact, and therefore probably 

 " in some sort of intercommunication with the antheridium, which 

 " latter organ is never wanting, is always of the same form and size, 

 " and originates in the same manner." He adduces the Phsenogams 

 as showing that impregnation may take place by mere contact, and 

 concludes that it may be assumed as very probable that the " Ei-zelle" 

 is impregnated by the antheridium, and that the perithecium of 

 Mysi])Jie (excepting the outer wall) is the product of sexual im- 

 pregnation. 



We are not aware of any other recent observations with regard 

 to the sexuality of the Fungi ; and we pass, therefore, to the conside- 

 ration of the Algge, in which family the greatest discoveries in 

 relation to impregnation have been made. 



Dr. Cohn, writing in the year 1855, says, " Until last year, few 

 botanists believed in the sexuality of the Algae;" and although this 

 remark went rather too far, when we consider that Thuret's obser- 

 vations were made in the year 18 i5, it tends to show how little v/as 

 known ten years ago in comparison with our present knovvledge. 



We will notice, in the first place, M. Thuret's observations on the 

 Fucaceae. It is to him that botanists are principally indebted for a 

 knowledge of the facts relative to sexuality and fecundation in that 

 tribe.* The organs of fructification of the Fucaceae are enclosed in 

 cavities under the epidermis of the frond, and which open on the 

 surface of the latter by a little pore or ostiolum. These cavities 

 contain two different kinds of organs. The one kind consists of 

 large bodies of an oval form, and an olive colour, attached to the 

 walls of the cavities by a short pedicel. These bodies are in some 

 genera simple, in others are divided into two, four, or eight spores. 



* See Comptes Rendus, t. xxvi. p. 745 ; Memoires de la Societe des Sciences 

 natiirelles de Chertourg, t. i. p. 161; Annales des So. Nat. 4 Ser. Vol. ii. p. ]!)7, 

 and Vol. vii. p. 35. 



