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292 PHILLIPS—A REVIEW OF PARTHENOGENESIS,  [{0ct. 16, 
3. Two Sexual Generations differing in form—Alloigony (Leuckart). 
(a) One free generation, one hermaphroditic and parasitic. 
e.g., Rhabdonema, Allantonema. 
(4) Seasonal Dimorphism. 
e.g., Lophyrus pint. 
Pzedogenesis or the parthenogenetic reproduction by larval 
forms is frequently met with (e.g., Diptera). This term was intro- 
duced by v. Baer (1864), but unfortunately it has since been 
applied by Seidlitz (1872), Dilling (1880) and others to all cases 
of sexually mature larve, even though the reproduction be truly 
sexual’ Thus they would include under this term the reproduc- 
tion of Axolotl and of Gyrodactylus. v. Siebold (1869) used the 
term pzdogenesis for the reproduction of the Strepsiptera, but in 
this case the sexually mature female is simply a degenerate adult 
and not a larval form as v. Siebold supposed, and the reproduction 
is sexual as far as the evidence at present goes. Toaid in the clear- 
ing up of this confusion of terms, Taschenberg (1892) suggests the 
term Proiogony for all cases of sexually mature larve, so that the 
word Peedogenesis can be used in its original and proper meaning. 
Chun (1892) uses the term Dissogonie for cases like those found by 
him in Cydifpe, where the same individual at different stages of 
development is sexually mature, and these stages are separated by a 
metamorphosis. 
The word Pseudoparthenogenesis has been applied by some 
writers to cases in which the eggs are fertilized from a seminal recep- 
tacle (¢ g., female eggs of Ags), and in which copulation does not 
take place for each egg. The use of such a word is unfortunate 
since it implies that there is a similarity to parthenogenesis, while 
there is really a very fundamental difference. 
INSECTA. 
HyMENOPTERA.—Besides the case of the Honey Bee referred to 
at some length on preceding pages, numerous other cases of par- 
thenogenesis occur among the Hymenoptera. 
Tenthredinide.—The first case described in this family was that 
of Mematus ventricosus (=. ribesiZ) by Robert Thom (1820) who 
wrote: ‘*The insect is male and female, but the ova of the 
female produce caterpillars, even when the male and female flies 
are kept separate. How long this offspring would continue to 
