1909] CURRENT LITERATURE 69 
that the réle of nutrition is secondary in nuclear division; that more importance 
should be attached to the proportion of carbon compounds in the protoplasm and 
to tendencies transmitted from ancestral forms; and that the constant occurrence 
of two nuclei has more than a nutritive significance. Their fusion must be 
regarded as of a sexual nature because of the fusion of two energids into one; 
because the result of the fusion is a sporogonium as in the case of the ordinary 
egg; because nuclear fusion necessitates a reduction of chromosomes; and because 
the formation of gametes on the gametophore recalls exactly the transformation 
of sporangia into conidiophores and has the same cause. 
The author believes that the nuclear fusion in asci and basidia really repre- 
sents the sexual reproduction in the higher fungi, and that the fourth theory 
mentioned is the true one, viz., that the ascus is a true sporogonium in all species 
and is therefore sporophytic in its nature. He believes that the primitive ancestral 
phycomycete had a greater or less resemblance to Myzocytium vermicolum. It 
possessed a thallus bearing sporangia, which, in his opinion, represented the 
sporophytic stage. The sporangia were very susceptible to external conditions. 
This was followed by a thallus bearing gametangia, the gametophyte; the fused 
gametes gave rise to the fertilized egg, which on germination produced a new 
sporangium or sporogonium with the characters of an ordinary sporangium, but 
with the doubled nuclei. This sporangium was but slightly susceptible to external 
conditions. The author believes that this point should be strongly insisted upon, 
that the ancestral type possessed two sorts of sporangia: the one responsive to 
environment has given rise, under the influence of aerial life, to the various types 
of conidiophores met with in the Ascomycetes; the other, of sexual origin, has 
been modified but little and has given rise to the ascus. 
The author proposes a new classification of the Ascomycetes, based on the 
reproductive organs, in which the whole group is divided into two, the Gamétangiées 
and Gamétophorées. The first possesses functional gametangia and includes 
Dipodascus and Eremascus. In the second the gametangia, if present, are no 
longer functional, and their place is taken by gametophores. 
About forty-five different types of Ascomycetes are described and figured in 
the major portion of the paper. One cannot but marvel that a single investigator 
could have found time to study all these forms in detail and with thoroughness. 
A most confusing use of terms makes the whole discussion difficult to follow.— 
Eras J. DuRAND 
Algal-animal symbiosis.—KEEBLE," continuing his interesting experimental 
investigation of the associations of unicellular algae with the low animals occurring 
on the larger seaweeds living between and just below the tide-limits on the north 
coast of France, now reports the occurrence of a unicellular brown alga in Convo- 
luta paradoxa, a tubellarian. He had previously found a green Chlamydomonas- 
tt KEEBLE, F., The eek cells of Convoluta paradoxa., Quart. Journ. 
Micros. Sci. 52: 431-479. 
