Sends his paper on the comparative anatomy of the assimilatory tissue systems of plants [Jahrb. Wiss. Bot. 13 (1882): 74–188]. This work has made clear to him how CD's principles produce rich results when applied to plant anatomy.
Also sends a paper on the difficult problem of the gulf between cryptogamic and phanerogamic plants in the evolutionary development, in order to present another proof of the continuity of the phylogenetic development of the plant kingdom.