June 15, 1900.] 



SCIENCE. 



923 



value of underdrainage and other methods 

 of reclaiming alkali lands.' The appropri- 

 ation for this Division is $5000 greater than 

 last year. 



The fund used in making investigations 

 as to the adaptability of the South for profit- 

 able tea culture was increased from $1000 

 to $5000. 



The fund provided for the Division of 

 Publications is $130,020, an increase of $28,- 

 360. The amount set aside for the printing 

 of Farmers' Bulletins is $22,500 greater than 

 last year. Four-fifths of the Farmers' Bul- 

 letins are to be sent out by members of 

 Congress instead of two-thirds as formerly. 



Other items of the appropriation act are 

 as follows : Biological Survey $30,300, an 

 increase of $2740 ; Division of Botany $43,- 

 080, an increase of $14,280; Division of 

 Pomology $18,400 ; Public Eoad Inquiry 

 $14,000, an increase of $6000 ; Division of 

 Statistics $146,160 ; Library $14,000 ; and 

 Museum $2260. 



The item of $200,000 for a new labor- 

 atory which was taken out of the Agricul- 

 tural Bill and put with those for other public 

 buildings in the Sundry Civil Bill failed to 

 pass. 



VARIATION AND SOME PHENONENA CON- 

 NECTED WITH REPRODUCTION 

 AND SEX. 



II. 



EFFECT OF CHANGED CONDITIONS IN ASEXUAL 

 EEPEODUCTION. 



This brings us to the consideration of the 

 question reserved : Are genetic variations 

 ever found in asexual reproduction ? 



If the views expressed in the earlier part 

 of this address are correct it would seem to 

 follow that genetic variations are variations 

 in the actual constitution, and are insepar- 

 ably connected with the act of conjugation. 

 The act of conjugation gives us a new con- 

 stitution, a new individuality, and it is the 



characters of this new individual in so far 

 as they differ from the characters of the 

 parents which constitute what we have 

 called genetic variations. According to this 

 the answer to our question would be that 

 genetic variations cannot occur in asexual 

 reproduction, and that if any indefinite 

 variability recalling genetic variability 

 makes its appearance* it must be part of 

 the genetic variability and directly trace- 

 able to the zygote from which the asexual 

 generations started. 



But if genetic variability is not found in 

 asexual reproduction the question still- re- 

 mains, can the other kinds of variations — 

 namely, those due to the direct action of 

 external forces upon the organism — be 

 transmitted in asexual reproduction ? Now 

 we have already seen that the effect of ex- 

 ternal agencies acting upon the organism 

 must be regarded under two heads, accord- 

 ing as to whether the reproductive organs 

 are or are not affected. If the reproductive 

 organs are not affected, then variations 

 caused by the impact of external forces will 



* Weismann, On Heredity, vol. ii, English edition, 

 p. 161. Warren, E. ' Observation on Heredity in 

 Parthenogenesis,' Proe. Roy. Soc. 65, 1899, p. 154. 

 These are the only observations I know of on this sub- 

 ject. They tend to show the presence of a slight vari- 

 ability, but they are not entirely satisfactory. In 

 connection with this matter I may refer to Weis- 

 mann's view that Cypris reptans, the species upon 

 which his observations were made, reproduces entirely 

 by parthenogenesis, and has lost the power of sexual 

 reproduction. This view is based on the fact that he 

 has bred forty consecutive parthenogenetic generations 

 and has never seen a male. As Weismann bases some 

 important conclusions on this view, with regard to 

 the importance of conjugation in rejuvenescence of 

 organisms, I may point out that the fact that he has 

 bred forty successive generations and has never seen 

 a male cannot be regarded as conclusive evidence that 

 males never appear. We know of many cases in 

 which reproduction can continue for more than forty 

 generations without the intervention of conjugation, 

 e. g., ciliated infusoria, many plants, and of other 

 species of Crustacea in which the male is very rare 

 and only appears after long intervals. 



