Mar. 1899.] BOTANICAL SOCIETY OF EDINBURGH 189 



noteworthy on several grounds. It shows an example of 

 false cross conjugation. In addition, there is also seen a 

 case of partial conjugation. Of the female cell, only a part 

 of the protoplast has conjugated, the other part remaining 

 sterile. The zygospore, further, is dumb-bell shaped, the 

 ends of the dumb-bell being in the male and female cell 

 respectively, and the constricted handle being in the con- 

 jugation tube. The spore, except for its peculiar position 

 and shape, appears perfectly normal, having membrane, 

 and so forth. This might be regarded as a case of 

 reversion, pathologically induced to a primitive Zygnema 

 type, where conjugation took place in the tube itself. 



Taking next, examples of conjugation between three 

 cells — two males belonging to one filament, and one female 

 to another, or belonging to three different filaments. Of 

 the latter condition no completed conjugations were found, 

 although all stages of attempted conjugation on these lines 

 are found, as see Figs. 24 and 25. Of the former, all 

 stages, from 'the incomplete to the complete condition, 

 occurred, and that very abundantly. Figs. 9 and 10 

 show two male cells which have sent out tubes towards 

 one female, which has developed one tube, by which it 

 conjugates with one of them. In Fig. 11 is seen the next 

 case, where the female has developed two tubes, meeting 

 those from the males, but only one male has conjugated. 

 Examples of this were very numerous. Fig. 12 shows a 

 curious condition, the same events have occurred as in 11, 

 but only part of the female protoplast has conjugated and 

 rounded off to form the zygospore ; another part has 

 apparently remained sterile. In Fig. 13 is seen the 

 perfect condition, where two males have conjugated with 

 one female through two sets of conjugation tubes. Those 

 of the female are now so close that they might be regarded 

 as branches of one broad tube. Traces of protoplasm still 

 remain in each male cell, and a detached fragment near 

 the mouth of one of the female tubes. In West's 

 paper is figured a specimen where the conjugation is 

 complete. 



Another series might be figured where the female sends 

 out one broad tube faceted to meet the two tubes from 

 the two male cells. All intermediate stages of this also 



