Figure 4. Idealized reconstruction of the life cycle of Synchytrum permicus sp. nov., silicified endoparasitic chytridiomycete from Skaar Ridge, Central Transantarctic Mountains, Antarctica.  The letters “A” and “S” refer to the asexual and sexual parts of the hypothesized life cycle. Diploid and haploid stages are indicated by “2n” and “n.” Figures not to scale. 1. Discharge of zoospores from mature thin-walled sporangia. 2. Dispersion of zoospores. 3. Encystment of zoospores on host tissue. 4. Ingression of zoospores into host cells. 5. Growth of zoospores. 6. Development of thin-walled sporangia. 7. Pairing up of zoospores. 8. Fusion of individual margins of zoospores. 9. Fusion of opaque central bodies of zoospores. 10. Encystment of zygotes on host tissue. 11. Development of encysted zygotes into young thick-walled sporangia. 12. Discharge of zoospores from mature thick-walled sporangia.