MONOGRAPH OF THE LAHOULBENI ACK.K. 



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side in two rows, below a common cavity into which they empty. In these instances 

 the antheridium lias no stalk-cell, and is closely united to the receptacle. In Campto- 

 myces and Eucantharomyces it terminates the appendage and is somewhat different 

 in character. In Camptomyces the antheridial cells are placed around and beside a 

 general cavity, and are arranged in several nearly vertical rows, emptying upwards 

 through short necks into this cavity, whence they escape through the terminal pore 

 of a short secondary neck (Plate VI, figs. 5 and 6). In Eucantharomyces the 

 antheridial cells are also arranged in nearly vertical rows, and are more numerous 

 than in the last mentioned genus. They empty into a general cavity, which is cen- 

 tral and terminal, and are discharged through a well-developed, though somewhat 

 irregular, secondary neck (Plate VII, fig. 27). hi both these genera the material has 

 been so limited in amount, and the antheridia are so difficult to observe by focussing 

 through the asymmetrical arrangement of their numerous antheridial cells, that I have 

 been unable to obtain a figure that would show satisfactorily the exact details of 

 structure and arrangement presented by the latter. The gross structure is, however, 

 made out without difficulty, and the general cavity is usually filled with very 

 numerous antherozoids, which here and there may be seen in process of formation 

 from the antheridial cells in a fashion exactly resembling that which occurs in the 

 instances previously described. 



A single type of compound antheridium remains to be mentioned, which occurs in 

 Haplomyces and in Cantharomyces, and in this instance also, owing to the lack of 

 sufficient material and to the complicated structure of the organ, much remains to 

 be learned concerning its exact structure. The type is distinguished from those 

 already mentioned from the fact that the secondary neck opens, as far as can be ascer- 

 tained from the material available, through a lateral pore, and consists of a central 

 cavity almost completely surrounded by the very numerous antheridial cells which 

 open into it. This general structure may be made out by focussing through the 

 organ ; but no further details have been visible in the specimens examined. The an- 

 theridium (Plate VII, figs. 3, 9, and 22) is identical in the two genera mentioned, 

 except that in Haplomyces it is terminated by a thorn-like cell, while in Cantharo- 

 myces it is placed below a well-developed sterile branching portion. With the 

 exception of Cantharomi/ces pusillus, which may possibly prove to represent a new 

 generic type, none of the species of these genera have been seen in a fresh condition, 

 and they are the only ones possessing compound antheridia in which the discharge of 

 the antherozoids has not been observed. The antheridium in these forms is the most 

 highly developed that has thus far been noticed, and further observations upon it 

 are greatlv to be desired. 



