NATURE OF THE SPERMATID 23 



of the secidium or its representative, and on the same my- 

 celium. For instance, in those cases where there is no gecidium, 

 but primary uredospores which are formed, like yecidiospores, 

 from a fusion-cell, followed by secondary uredospores which are 

 not so formed although similar in all other respects — then the 

 primary spores alone are accompanied by the spermogones. 

 This argument is the most decisive. 



(2) Their size and character. They are much smaller than 

 the other spore-forms, with thin walls, a large and not very 

 degenerate nucleus though often without a nucleolus, little 

 protoplasm and no reserve-stuff (oil, etc., with which the 

 ordinary spores of the Uredinales are so richly provided), thus 

 reminding one of the spermatia of the Floridere. 



Sharp (1911) reports, in Puccinia Podophylli, spermatia 

 three times as long as the nucleus, and therefore containing 

 some appreciable amount of cytoplasm. But protoplasm is not 

 reserve-stuff. 



(3) They will not reproduce the species. All the efforts 

 that have been made to cause them to do so have uniformly 

 failed. All the other reproductive cells of these Fungi can be 

 successfully used for that purpose, if applied to the proper host. 

 In some species, as Cronartium ribicola, the spermatia can be 

 collected in large quantities: Klebahn made numerous trials 

 with them, but entirely without result. Jaczewski and others 

 have confirmed his experience. It is a commonplace observa- 

 tion that highly specialised male cells cannot in themselves 

 reproduce the species, while female cells can, as in the cases of 

 parthenogenesis, both true and false. This difference in be- 

 haviour is partly correlated with the difference in the amount 

 of food-reserve available, with which the larger female gametes 

 are usually well supplied. In conjugation, where the two 

 (male and female) gametes are approximately of equal size (as 

 in certain Mucorini), each may form a functional azygospore. 



(4) They will hardly germinate in water, probably because 

 they have no reserve-food. If food is supplied by cultivating 

 them in nutrient solutions, a little growth is obtained, but it 

 is very insignificant and soon perishes. The same thing is 

 true of male cells in other organisms. Conidia, under such 



