TERATOLOGY IN MODERN BOTANY. 87 



to be quite sterile, whilst of the offspring of other, more 

 robust examples, sterility occurred in only a very few cases. 

 The experiments of Heinricher ^ must, lastly, be men- 

 tioned. He found that a second whorl of stamens which 

 is normally absent when it did occur could be hereditarily 

 transmitted. The precise form of the members of this 

 whorl is, indeed, subject to great variation. The 

 stamens are sometimes stunted, at others fully developed, 

 sometimes they were replaced by staminodes, with or with- 

 out pollen sacs, at other times they were reduced to mere 

 scar-like structures. Complete fixation, i.e., the cultivation 

 of stocks yielding only six-stamened flowers has not yet 

 been attained. A point of special interest is that flowers 

 also occurred in which the inner perianth whorl was con- 

 structed in exactly the same way as the outer one, so that 

 the form of flower in this case presented a great variation 

 from the normal one, and might perhaps be regarded as an 

 exaggerated reversion to an ancestral type. 



II. 



On the other hand, a number of cases are now on record 

 in which malformations have been successfully produced by 

 artificial means. We do not include in this category such 

 appearances as result from insufficiency of light, conditions 

 of temperature, and so on. The lower plants, especially 

 the moulds, have proved to be particularly adapted for these 

 observations. 



Raciborski has recently produced interesting malforma- 

 tions in Basidioboliis ranartun." This mould consists nor- 

 mally of cells containing a single nucleus, which are 

 cylindrical in form and arranged in rows. The fungus 

 is one which can be easily cultivated. If cultures be made 

 in 10 per cent. Glycerine solution, and kept at a somewhat 

 high temperature (30 C), there are very often developed 

 (though all the cells do not react alike) giant-cells of 6o^t in 



1 Versuche liber die Yererbung der Ruckschlagserscheinungen bei 

 Pflanzen," Fj-higs. /ahrb., xxiv. 



2 M. Raciborski, Ueber den Einfluss ausserer Bedingungen auf d. 

 Wachsthumsweise d. Basidiobolus ranaru/n. 



