144 BOTANICAL GAZETTE. 



oospore — and the same is true for an egg, etc., the terms being 

 different — simply a renewal of the growth of the organism ; and 

 from this and other convictions follows the result that the forma- 

 tion of an oosphere, although it may take place after an accumu- 

 lation of large quantities of food, implies a condition of weari- 

 ness — if the term may be allowed — on the part of the protoplasm 

 for the time being. No doubt the molecular energy of the pro- 

 toplasm forming the oosphere, is less than that of the rest of the 

 plant for the time being; the access of the antherozoid or male 

 protoplasm, however, reinvigorates the sluggish mass, and re- 

 newed life ensues. This may require some time, however, and 

 we may possibly not be far wrong if we imagine that interval to 

 be occupied in molecular rearrangements in the mass. 



But, although we can sum up the foregoing by saying that, 

 after a time, protoplasm requires reinvigorating by the addition 

 of fresh protoplasm from another source, it is extremely improb- 

 able that the protoplasm of the male and female organs is at all 

 similar. 



It now remains to be seen if we can throw any light on the 

 curious disappearance of sexual organs and sexuality in the Fungi 

 — curious, because the sexual process appears to be all but uni- 

 versal in all organisms excepting the very lowest. 



A hypothesis which suggests itself, and which Eidam 1 favors, 

 and which is certainly supported by some analogies, is to the 

 effect that the apogamous Fungi, i. e., those in which the sexual 

 organs are totally suppressed, are not always apogamous. "We 

 know that many forms only produce their sexual organs at com- 

 paratively long and rare intervals. The Mucors, for instance, 

 may be propagated through numerous generations by means of 

 the asexual spores ; the sexual organs only arising now and again 

 under favorable conditions. 



Moreover, the cases of polyembryony — where several embryos 

 arise in an embryo sac, although only one oosphere is fertilized — 

 favor the view that the effect of fertilization may be extensive; 

 and we can not doubt that such is the ca*se where adventitious 

 covering branches arise after the conjugation of certain Mucorini, 

 and in the Orchidece, where fertilization or even the mere growth 

 of the pollen tube affects the whole flower. 



The sexual act, however, consisting as it does simply or mainly 

 in the reinvigoration of protoplasm by the addition of proto- 

 plasm of a different nature (though we do not know the kind or 

 limit of difference), it may be that an explanation of what occurs 



1 Cohn's Beitr. zur Biologie, etc., B. iii, H. iii. 



